integrated livestock-fish farming systems · box 1.e challenges to sustainable farming in the red...

Integrated livestock-fishfarming systemsIntegrated livestock-fishfarming systems

Integrated livestock-fishfarming systemsBY D.C. LITTLE AND P. EDWARDS

INLAND WATER RESOURCES AND AQUACULTURE SERVICEANIMAL PRODUCTION SERVICE

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONSROME 2003

All rights reserved. Reproduction and dissemination of material in this information product for educational or other non-com-mercial purposes are authorized without any prior written permission from the copyright holders provided the source is fullyacknowledged. Reproduction of material in this information product for resale or other commercial purposes is prohibited with-out written permission of the copyright holders. Applications for such permission should be addressed to the Chief, PublishingManagement Service, Information Division, FAO, Viale delle Terme di Caracalla, 00100 Rome, Italy or by e-mail to [email protected]

©FAO 2003

The designations employed and the presentation of material in this informationproduct do not imply the expression of any opinion whatsoever on the part ofthe Food and Agriculture Organization of the United Nations concerning thelegal or development status of any country, territory, city or area or of itsauthorities, or concerning the delimitation of its frontiers or boundaries.

Preparation of this documentThis book was prepared by the authors under the overallcoordination of Matthias Halwart, Fishery Resources Officer (Aquaculture)and with the collaboration of colleagues from Animal Production Service,particularly Manuel Sanchez and Simon Mack, who contributed comments.The printing of the publication was supported by the InterdepartmentalWorking Group on Integrated Production Systems. Graphic design byJoanne Morgante. All photos by D.C. Little.

ISBN 92-5-105055-4

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Preface

Small farmers in developing countries are poorer thanthe rest of the population, often not getting enough food to lead normal, healthyand active lives. Dealing with poverty and hunger in much of the world thereforemeans confronting the problems that small farmers and their families face intheir daily struggle for survival. One option for economically and ecologicallysustainable development of farming systems is the integration of agricultureand aquaculture.

The various types of aquaculture form a critical component withinagricultural and farming systems development that can contribute to thealleviation of food insecurity, malnutrition and poverty through the provision offood of high nutritional value, income and employment generation, decreasedrisk of production, improved access to water, sustainable resource managementand increased farm sustainability.

Livestock production and processing generate by-products that may beimportant inputs for aquaculture. The main linkages between livestock and fishproduction involve the direct use of livestock wastes, as well as the recycling ofmanure-based nutrients which function as fertilizers to stimulate natural foodwebs.

On a global basis, most cultured freshwater fish are produced in Asia insemi-intensive systems that depend on livestock wastes purposely used inponds, or draining into them. Much of the vast increase in China’s recent inlandaquaculture production is linked to organic fertilization, provided by the equallydramatic growth of poultry and pig production. The use of livestock wastes isstill needed, even when high-quality supplementary feeds are available and theyare still widely used in more intensive aquaculture systems.

The objective of the publication is to provide an analysis of the evolutionand current status of integrated livestock-fish systems in Asia, particularly Eastand Southeast Asia, as well as to provide a sound technical basis for consideringtheir relevance for the planning of livestock-fish systems in Africa and LatinAmerica.

It is hoped that the conclusions and recommendations presented here willbe interesting and thought-provoking for a wide audience generally interestedin the subject of integrated agriculture-aquaculture, and particularly policymakers, planners, NGOs and senior research and extension staff. It is hoped thatthe book will stimulate these people at all levels to ensure that agriculturaldevelopment provides for reasonable rural livelihoods, a clean environment, andadequate food products.

Jiansan Jia - Chief, Inland Water Resources and Aquaculture Service

Irene Hoffmann - Chief, Animal Production Service

Contents1 Introduction 1

1.1 Rationale of the Study 1

1.2 Definitions of Integrated Farming 2

1.3 Potential Linkages Between Livestock and Fish Production 2

1.4 Relevance of Integrated Farming 4

1.5 Sustainability Issues at Micro- and Macro-Levels 51.5.1 MICRO-LEVEL 51.5.2 MACRO-LEVEL 10

2 Evolutionary Development of Integrated Livestock-Fish Farming Systems in Asia 132.1 Systems and Scale 13

2.2 Environmental Effects 15

2.3 Crop Domination 16

2.4 Integrated Crop/Livestock 20

2.5 Industrial Monoculture 21

3 Major Types of Integrated Systems in Asia 233.1 Current Status 24

3.1.1 GENERAL CONSIDERATIONS 243.1.2 MONOGASTRICS 253.1.3 RUMINANTS 293.1.4 NON-CONVENTIONAL LIVESTOCK 30

3.2 Upgrading Traditional Livestock Systems for Aquaculture 313.2.1 UPGRADING LIVESTOCK DIETS AND

PRODUCTION SYSTEMS 323.2.2 COLLECTION OF MONOGASTRIC WASTES IN

SMALL-HOLDER SYSTEMS 333.2.3 RUMINANT SYSTEMS 343.2.4 MIXED INPUT SYSTEMS 36

3.3 Integration with Agro-Industry 403.3.1 GENERAL CONSIDERATIONS 40

4 Environmental Aspects 474.1 Nutrients 48

4.1.1 NUTRIENT RECYCLING IN AGROECOSYSTEMS 494.1.2 NUTRIENT EFFICIENCY IN LIVESTOCK 524.1.3 NUTRIENT EFFICIENCY IN AQUACULTURE 524.1.4 NUTRIENT RELATIONSHIPS IN LIVESTOCK-FISH SYSTEMS 53

iv INTEGRATED LIVESTOCK-FISH FARMING SYSTEMS

1

2

3

4

4.2 Significance of Livestock and Fish Production in the Global Environment 544.2.1 GLOBAL WARMING 544.2.2 WATER USE 554.2.3 BIODIVERSITY 564.2.4 USE OF FISHERIES TO SUPPORT LIVESTOCK AND

FISH PRODUCTION 584.2.5 IMPACTS OF LIVESTOCK SYSTEMS ON FISH PRODUCTION 58

5 Design Criteria for Livestock Manured Ponds 615.1 Manured Pond Dynamics 61

5.1.1 OVERVIEW 615.1.2 PRINCIPLES OF FERTILIZATION 645.1.3 PRINCIPLES OF SUPPLEMENTARY FEEDING 67

5.2 Waste Characteristics 695.2.1 GENERAL CONSIDERATIONS 695.2.2 SPECIES, SIZE AND SEX 715.2.3 FEED AND WASTE MANAGEMENT 715.2.4 NUTRIENT RELEASE FROM MANURES 765.2.5 WASTE COLLECTION AND STORAGE 76

5.3 Waste Addition 79

6 Public Health and Livestock-Fish 856.1 General Considerations 85

6.1.1 PATHOGENS 866.1.2 BACTERIA AND VIRUSES 876.1.3 PARASITES 896.1.4 INSECT-VECTOR BORNE DISEASES 926.1.5 INFLUENZA PANDEMICS 92

6.2 Chemical Hazards and Associated Risks 93

6.3 Biological Hazards 95

6.4 Summary 100

7 Social and Economic Considerations 1017.1 Demand 103

7.2 Nutritional Benefits 106

7.3 Gender and Age 108

7.4 Resource issues 1117.4.1 INTRODUCTION 1117.4.2 MICRO-LEVEL 1117.4.3 MACRO-LEVEL 1177.4.4 BENEFITS 118

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6

7

7.4.5 RISK 1187.4.6 LABOUR 120

7.5 Promotion of Integrated Livestock-Fish 1237.5.1 FRAMEWORK 1237.5.2 DEVELOPING HUMAN CAPACITY 1247.5.3 SYSTEMS APPROACH 1247.5.4 FARMER-FIRST 1247.5.5 CONVENTIONAL APPROACHES 1257.5.6 ALTERNATIVE APPROACHES 1267.5.7 EXTERNAL FACTORS 129

8 Transferability of Asian Experiences to Africa and Latin America 1318.1 General Considerations 1318.2 Information Needs 1358.3 Institutional Constraints 1358.4 Seed Supply 1388.5 Theft and Predation 1398.6 Demand 1398.7 Multipurpose Use and Benefits 1408.8 Beneficiaries 1418.9 Comparing the Regions 143

9 Future Directions in Livestock-Fish Integration 1459.1 Demand and Globalization 1459.2 Feed Resources 1469.3 Intensification not Concentration 1479.4 Peri-Urban Integration 1489.5 Rural Integration 1519.6 Potential 156

Acknowledgements 159References 161

vi INTEGRATED LIVESTOCK-FISH FARMING SYSTEMS

8

9

List of TablesTable 1.1 How the integration of fish culture into small-holder crop/livestock systems affects asset

accumulation and livelihoodsTable 1.2 How livestock and fish improve the sustainability of farming systemsTable 2.1 Comparison of common property management and scope for intensification in water-scarce and

flood-prone environmentsTable 3.1 Matrix of livestock waste qualities and suitability for use in aquacultureTable 3.2 Change in frequency of pond inputs before and after extension in Kapsia Thana, Gazipur District,

BangladeshTable 3.3 Impacts of the use of wastes from ducks fed supplements to scavenging, in addition to inorganic

fertilisation, on overall system feed efficiency and yield.Table 3.4 Feed and fertilizer inputs in integrated systems for three areas with different levels of production

in ChinaTable 3.5 Economic comparison of different fertilizers with respect to available nitrogen (N),phosphorous (P)

and carbon (C).Table 4.1 Efficiency of N recovery in ponds stocked with Nile tilapia and fertilised with livestock wasteTable 4.2 Water consumption of fish production integrate with livestock or as a stand-alone enterpriseTable 4.3 Potentials and constraints to integration of livestock with fish by systemTable 5.1 Factors affecting use of animal wastes in pondsTable 5.2 Input and output of poultry waste fed-aquacultureTable 5.3 Effect of feeding and management on waste characteristics of livestockTable 6.1 Main types of parasitesTable 6.2 Chemical hazards and associated risks to fish productionTable 7.1 Adoption of livestock wastes and other inputs in fish culture in NE ThailandTable 7.2 Livestock inventories and fertilisers used in an on-farm trial with farmers in Udorn Thani, Northeast

ThailandTable 7.3 Characteristics of pig production in three areas of Southeast AsiaTable 7.4 Factors that reduce smallholders' risk through production of livestock, fish or both.Table 8.1 Issues and problems from the perspective of aquaculture promoters in Africa, Latin America and

AsiaTable 9.1 Measures to intensify livestock and fish production without spatial concentrationTable 9.2 Aspects of multipurpose use of a water body involving livestock and fish production

List of BoxesBOX 1.A Checklist of key issues affecting linkages between livestock and fish productionBOX 1.B A widely used definition of sustainabilityBOX 1.C Livelihoods definedBOX 1.D Agribusiness view of sustainabilityBOX 1.E Challenges to sustainable farming in the Red River Delta, Viet NamBOX 1.F A decline in integrated farming in China?BOX 2.A Disease constrains livestock productionBOX 2.B Intensification of ruminant and macrophagous fish have similar constraintsBOX 3.A Case study of integrated farming in Central Thailand

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viii INTEGRATED LIVESTOCK FISH FARMING SYSTEMS

BOX 3.B Constraints to integration of traditional livestock and fish productionBOX 3.C Key indicators of the potential for upgradingBOX 3.D Upgrading scavenging poultry diets and management in EthiopiaBOX 3.E Changing integrated systems in ChinaBOX 3.F Summary of factors affecting use of inorganic fertilizer and feeds with livestock wastesBOX 3.G By-products from livestock and processing wasteBOX 3.H Green blowfly larvae used to process pig manure to fish feedBOX 3.I Chicken slaughter house waste fed to catfishBOX 3.J Feeding maize to catfishBOX 4.A Nutrient flows among village subsystems and between village and outside systems in Nguyen Xa

village, Viet NamBOX 4.B Approaches to reducing livestock wastes and environmental pollutionBOX 4.C Summary of nutrients and the environmentBOX 4.D A need for water encourages integrated fish cultureBOX 4.E Summary of factors through which livestock and fish interact with the global environmentBOX 5.A Benefits of animal manures in pond cultureBOX 5.B Fixed fertilization rates defined by experimentationBOX 5.C High loadings of ruminant manureBOX 5.D Categories of supplementary feedingBOX 5.E Disappointing results with supplementary feedingBOX 5.F Summary of key factors affecting manured pond dynamicsBOX 5.G Goat management level affects nutrients collectable for aquacultureBOX 5.H Quantity of supplementary feed affects scavenging poultry wastes and fish productionBOX 5.I Integration of duck and fish production in ricefields in the PhilippinesBOX 5.J Impacts of supplementary feed quality on waste characteristicsBOX 5.K Summary of factors affecting livestock waste characteristicsBOX 5.L Pornsak's duck slaughterhouse in Bang Lane, Central ThailandBOX 5.M Surin's use of duck manure in Nakon Pathum, ThailandBOX 5.N Factors affecting characteristics of livestock waste and its use for aquacultureBOX 5.O Questions to ask during the design of livestock-fish systemsBOX 6.A Key points to reducing public health risks from pathogens in livestock-fish systemsBOX 6.B Safety issues as aquaculture stimulates changes in household pig production in Lao PDRBOX 6.C Key points to reducing public health risk due to parasites and other biological and chemical agentsBOX 7.A Summary of key points relating to social and economic issuesBOX 7.B Building social assetsBOX 7.C Poor quality control hinders export of value-added fish productsBOX 7.D Summary of demand related issuesBOX 7.E Nutritional importance of fishBOX 7.F Access and benefits from aquacultureBOX 7.G Training women in aquacultureBOX 7.H Intra-household relationships affect production and consumptionBOX 7.I Summary of key points relating to role of gender in integrated aquacultureBOX 7.J Overcoming constraints to using livestock waste in Northeast ThailandBOX 7.K Contrasting rice land holding, rice yield and pig productionBOX 7.L Hybrid maize enhances integrated approachBOX 7.M Increasing the village pig herd in a village in Northeast Thailand-potential impacts on fish

productionBOX 7.N Summary of key resource issuesBOX 7.O Development of livestock-fish systems in Asia

BOX 7.P Development of integrated livestock-fish production in the provinces around Bangkok, ThailandBOX 7.Q "Top down" small-scale duck-fish integration failsBOX 7.R An approach to understanding constraints to fish production in rain-fed cascade tank systems in

the Dry Zone, Sri Lanka.BOX 8.A Stages in aquaculture development to serve local demandBOX 8.B Poorly targeted research for resource-poor farmersBOX 8.C Institutional issues constraining aquaculture development common to Asia, Africa and Latin

AmericaBOX 8.D Constraints to fish seed production in AfricaBOX 8.E Promoting self-sufficiency of fish seedBOX 8.F What happens to famed fish in rural Africa, Latin America and Asia?BOX 8.G Factors affecting the success of integrated livestock aquaculture in community managed water

bodies in Northeast Thailand and Lao PDRBOX 8.H Promoting community-level aquaculture in PanamaBOX 8.I A failed attempt at community aquaculture in NigeriaBOX 8.J Factors influencing the relatively lower success of rural aquaculture in Africa and Latin America

than AsiaBOX 9.A Possible policies to discourage concentration of intensive livestock and fish productionBOX 9.B Singapore phases out pig productionBOX 9.C Separation of solid and liquid fractions improves the efficiency of livestock waste use in farming

systemsBOX 9.D Changing opportunities for smallholders to integrate egg-duck and fish productionBOX 9.E Assessing efficiency of traditional, upgraded and modern livestock systemsBOX 9.F Feeding pigs on small fish

List of FiguresFigure 1: The development of sustainable aquaculture systems involves consideration of production

technology, social and economic aspects, and environmental aspects (Source: AIT, 1994).Figure 2: Potential outcomes of livestock-fish integrationFigure 3: Main and secondary linkages in livestock-fish integrationFigure 4: Asset pentagons to analyse sustainable rural livelihoodsFigure 5: Evolutionary development of integrated farming systemsFigure 6: Classification of livestock production and relationship to value of livestock waste for aquacultureFigure 7: Percentage of farms using various fertilizer and supplementary feed inputs for fish culture in

Central Thailand (a) manure (b) rice and grain products (c) waste food from human consumptionand agro-industry (d) animal by-products and animal feed (e) vegetable matter

Figure 8: Livestock present and integrated on fish farms in Central Thailand by type and number of livestock Figure 9: Percentage yield by fish species in three areas of productivity in ChinaFigure 10: Comparison of possible strategies for using livestock production and processing wastes in

aquacultureFigure 11: Percentage of farms in Central Thailand using various fertiliser and supplementary feed inputs for

fish culture (a) waste food from human consumption and agro-industry (b) animal by-products andanimal feed (c) vegetable matter

Figure 12: The two-way interaction between aquaculture and the environment involves numerous factorsthat range from positive to negative in their impact

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x INTEGRATED LIVESTOCK-FISH FARMING SYSTEMS

Figure 13: Nutrient cycles for an agro-ecosystem involving crops, fish and livestockFigure 14: Nutrient flows among village subsystems and between village and outside systemsFigure 15: Mean dissolved oxygen (DO) in mg I-1 at dawn for ponds receiving different levels of manure

loading. Error bars show standard deviationFigure 16: Schematic depiction of changes in the natural food organisms and fish yields, in relation to

standing crop of the cultured organism and the ensuing protein needs of the supplemental feed (s) Figure 17: Annual production of nitrogen in faeces and urine for various livestockFigure 18: Goat production and total collectable nutrients in different management systems. 1= Stall feeding

with fodders and concentrate-wastes collected daily; 2=daytime tethered grazing and ricebransupplement-wastes collected daily; 3=daytime tethered grazing and legume leaf supplement-wastes collected daily; 4=daytime tethered only, wastes collected daily; 5=daytime tethered only,wastes collected monthly

Figure 19: Egg laying rate of Khaki-Campbell x local strain fed two differents supplementary diets,T1 unhulled paddy rice and T2 village rice bran

Figure 20: Dry matter (DM), total nitrogen (N) and total phosphorous (P) in wastes of ducksFigure 21: Loss of total nitrogen in fresh egg-laying chicken manure with timeFigure 22: Rates of faecal coliform (grey line) and bacteriophage (blue line) die-off in septage loaded pondsFigure 23: Schema showing main possible resource flows in conventional mixed farming and the alternative

use of livestock wastes in fish productionFigure 24: Annual distribution by crop of labour input into the dike-pond system, Zhujiang Delta, ChinaFigure 25: Schema of the major interactions between the various subsystems in a crop/ livestock-fish

integrated farming systemFigure 26: What factors stimulate feed or waste-based aquaculture?

CHAPTER 1 • INTRODUCTION 1

Introduction

1

Aquaculture is the fastest growing food production sector in

the World with annual growth in excess of 10 percent over the last two decades.

Much of this development has occurred in Asia, which also has the greatest variety of

cultured species and systems. Asia is also perceived as the ‘home’ of aquaculture, as

aquaculture has a long history in several areas of the region and knowledge of

traditional systems is most widespread. Furthermore, the integration of livestock and

fish production is best established in Asia.

In this initial section we introduce the rationalefor the study and provide definitions ofintegrated livestock-fish farming. We thenexamine the current status and futureimportance of livestock and fish productionbeing integrated rather than being developedfurther as specialized, separate activities. Theirsustainability and importance in a broadercontext are then considered.

Rationale of the studyLivestock-fish production systems develop tosatisfy needs if they fit into the resource base or

environment, and if they are socially andeconomically viable. Macro-level factors may alsohave a significant influence and there are environ-mental implications, both on- and off-farm, for thedevelopment of sustainable systems (Figure 1).

The current status of livestock-fish systemsreflects their evolution in response to changingcircumstances: the past history of currentsystems is not generally appreciated; nor is theirfuture potential apparent.

The rationale for this study is to interpretAsian, especially East and Southeast Asianexperience in integrated systems throughanalysis of their evolution and current status andto consider their relevance for livestock-fishplanning in Africa and Latin America.

1.1

Definitions of integratedfarmingIntegrated farming is commonly and narrowlyequated with the direct use of fresh livestockmanure in fish culture (Little and Edwards, 1999).However, there are broader definitions that betterillustrate potential linkages. Indeed, the term‘integrated farming’ has been used for integratedresource management which may not includeeither livestock or fish components. Our focus isthe integration of livestock and fish, often withina larger farming or livelihood system. Althoughhousing of livestock over or adjacent to fish pondsfacilitates loading of wastes, in practice livestockand fish may be produced at separate locationsand by different people yet be integrated. Chen etal. (1994) distinguished between the use ofmanures produced next to the fishpond andelsewhere on the same farm. A wider definitionincludes manures obtained from off-farm andtransported in bags, e.g. poultry manure, or as a

slurry in tanks, such as for pig and large ruminantmanure.

Integrated farming involving aquaculturedefined broadly is the concurrent or sequentiallinkage between two or more activities, of whichat least one is aquaculture. These may occurdirectly on-site, or indirectly through off-siteneeds and opportunities, or both (Edwards, 1997).Benefits of integration are synergistic rather thanadditive; and the fish and livestock componentsmay benefit to varying degrees (Figure 2). Theterm “waste” has not been omitted because ofcommon usage but philosophically andpractically it is better to consider wastes as“resources out of place” (Taiganides, 1978).

Potential linkages betweenlivestock and fish productionThe main potential linkages between livestockand fish production concern use of nutrients,particularly reuse of livestock manures for fish

1.3

1.2

2 INTEGRATED LIVESTOCK-FISH FARMING SYSTEMS

The development of sustainable aquaculture systems involves consideration ofproduction technology, social and economic aspects, and environmental aspects

FIGURE 1

Production Technology

Social and Economic Aspects

Environmental Aspects

Productive

EnvironmentallyCompatible

Socially Relevant and Profitable

SustainableAquaculture

System

Source: AIT (1994)

production. The term nutrients mainly refers toelements such as nitrogen (N) and phosphorous(P) which function as fertilizers to stimulatenatural food webs rather than conventionallivestock nutrition usage such as feedingredients, although solid slaughterhousewastes fed to carnivorous fish fall into the lattercategory. There are also implications for use ofother resources such as capital, labour, space andwater (Figure 3). A variety of factors affectpotential linkages between livestock and fishproduction (Box 1.A).

Both production and processing of livestockgenerate by-products that can be used foraquaculture. Direct use of livestock productionwastes is the most widespread andconventionally recognized type of integratedfarming. Production wastes include manure,urine and spilled feed; and they may be used asfresh inputs or be processed in some way beforeuse.

Use of wastes in static water fishpondsimposes limitations in terms of both species andintensity of culture. Stimulation of natural foodwebs in the pond by organic wastes can supportrelatively low densities of herbivorous andomnivorous fish but not a large biomass of

carnivorous fish. These biological processes arealso temperature dependent. The optimaltemperature range is between 25-32°C although


Separate, stand alone operations

Integration increases level of benefit of one component and has a neutral

effect on the other

Integration results in similar levels of benefit toboth components, which increases overall benefit

Small declines for one component are compensated for the large increase in the other

Potential outcomes of livestock-fish integration

FIGURE 2

� Is there demand for fish species capable of feeding on natural foods generated byfertilization using livestock wastes?

� Are the livestock monogastrics or rumi-nants?

� Can the wastes be cost effectively collect-ed?

� Will legislation require processing ofwastes before use for fish culture?

� Do livestock wastes have a high opportuni-ty cost?

� Will low ambient temperatures (<18°C)restrict waste-fed aquaculture?

� Is fish culture already established based on conventional feeds and systems?

Checklist of key issues affectinglinkages between livestock and fish production

BOX 1.A

waste-fed aquaculture in sub-tropical andtemperate zones where temperatures riseseasonally has also been successful. Processingwastes through organisms such as earthwormsand insect larvae that feed on them andconcentrate nutrients to produce ‘live feeds’ is analternative approach to raising fish needing highlevels of dietary animal protein. Livestockprocessing can also provide a wide variety ofwastes that vary from dilute washing water tohigh value meat and bloodmeal that can be usedas high value fish feeds or feed ingredients. Ifenough of these types of feeds are available, highdensity and intensive production of carnivorousfish species can be supported. Aquaculture mayalso provide inputs and other benefits to livestockproduction. A variety of aquatic plants e.g.duckweeds and the aquatic fern Azolla haveproven potential as livestock feeds; andinvertebrates such as snails and crustaceans canbe used for poultry feeds.

Our study focuses on the integration of fishand livestock. The use of cultured fish or fish

products as livestock feeds, although currentlyuncommon, holds promise and is reviewed.Other, more minor beneficial linkages betweenfish and livestock production include use of fishculture water for drinking/bathing livestock andcooling livestock housing. Nutrients contained inculture water and sediments may be used toproduce arable crops for livestock. The viability ofthese options depends on a variety of factors,including the types of livestock and fish that canbe raised profitably and the production systemsused.

Relevance of integratedfarmingThe integration of fish and livestock production isprobably closer today, and more important thanever before (FAO, 2000). On a global basis mostcultured freshwater fish are produced in Asia insemi-intensive systems that depend on fertilizer

1.4


FIGURE 3

Feed

Livestock Human

main flows

secondary flows

Human

abattoir waste

Urine

Waste feed

Manure

Dri

nkin

gC

oolin

g

Water

Irrigation

Fish

P

P

P

P

Main and secondary linkages in livestock-fish integration (P = processing)

nutrients. Moreover, with increasing need formultipurpose use of water resources, communitywater bodies used for watering livestock areincreasingly stocked with fish seed and theirmanagement intensified. Several studies ofsmall-holder aquaculture in Bangladesh, India,Thailand and Viet Nam indicate that livestockwastes are the most commonly used input. Fishyields may not be optimized for a variety ofreasons but livestock wastes purposely used inponds, or draining into them, support theproduction of most cultured fish in Asia.

An analysis of China, the ancestral home ofaquaculture, indicates that whilst intensivepractices based on formulated pelleted feed aredeveloping rapidly, much of the vast increase inChina’s recent inland aquaculture production islinked to organic fertilization, provided by theequally dramatic growth of poultry and pigproduction. Trends in those parts of Asia whichare undergoing rapid industrialization andurbanization suggest that livestock-fish systemscan retain a relative advantage over intensiveaquaculture for production of low-cost carps andtilapias. A strong link to the use of livestockwastes remains even when high-qualitysupplementary feeds are available and widelyused.

A major issue is the potential competition for,and relative efficiency of the use of, limitedamounts of feeds between livestock and farmedfish. This has both local and global implications.Supplementary feeds, such as ricebran and oilcakes, which are traditionally fed to livestock, areoften in demand for feeding fish. Continuedgrowth in demand for livestock and fish hasraised alarm bells over the sustainability of feedsupplies and the impacts of such growth on theenvironment.

Sustainability issues atmicro- and macro-levelsSustainability may be considered at global,national, regional, community and householdlevel and from a variety of perspectives.Sustainability as defined by an ecologist, may be

very different to that by an economist, but mostcan support the essence of that in theBrundtland Report (WCED, 1987) whichincorporates social and economic as well asenvironmental concerns. Important questionsrelate to the role of integration of aquaculturewith livestock to improve sustainability of foodproduction in socially and economicallyadvantageous ways while safeguarding orimproving the environment. For this to occur, theroles of culture and institutions both have to beconsidered also since they are major forces forchange or conservatism. A major issue of thisbook is how integration, rather thanspecialization and separation, of livestock andfish production can enhance sustainability at alllevels and perspectives.

1.5.1 MICRO-LEVEL

The interpretation and measurement ofsustainability have become focal points of ruraldevelopment. In a smallholder farmer’s world, keyparameters of sustainability have been identifiedas high levels of species diversity, nutrientcycling, capacity (total production) and economicefficiency (Lightfoot et al., 1993; Bimbao et al.,1995; Dalsgaard et al., 1995). At the micro-level,watershed, community, farm, plot and pond maybe used as a basis for assessing sustainability,but the role of people is central to development.

Most poor rural people do not rely entirely ontheir own land to sustain them. Typicallivelihoods are complex and depend on a varietyof resources, many of which are off-farm (Ellis,1992). At the heart of the issue of ‘sustainability’are peoples’ livelihoods (Box 1.C). Holistic

1.5


“Sustainable development is that whichmeets the needs of the present withoutcompromising the ability of future gener-ations to meet their own needs”

Source: WCED (1987)

A widely used definition of sustainability

BOX 1.B

thinking is required to analyse and describelivelihoods with a focus on peoples’ relativestrengths rather than ‘needs’. Building up assetsis a core component of empowerment (Figure 4).How the inclusion of intensified management ofaquatic resources can support, or detract, fromthis process is indicated in Table 1.1.

People base their livelihoods on a range ofassets in addition to financial capital thatinclude natural, human, physical and socialcapital. A pentagon can represent these fivetypes of asset or capital although in practice

there is overlap between them (Figure 4).Understanding trends in peoples’ assets overtime can indicate if positive or negativedevelopments are occurring, and if livelihoodsare deteriorating or improving. The approachcan be applied on a community, group orhousehold level to inform and guide thedevelopment process. Knowing about the assetsof different wealth and social groups in the samecommunity can allow better targeting of poorerpeople and monitoring of changes that occur.The impacts of shocks of various types, and howassets are used to reduce vulnerability, areimportant aspects of assessing livelihoods.

Forging links between ecosystem theory andfarming system analysis (Dalsgaard et al., 1995) canbe useful, provided that the results are placedwithin a broader framework of sustainabilityissues. A range of different system attributes hasbeen identified that provides measures of howlivestock and fish can improve sustainability offarming systems (Table 1.2). As sub-systems with-in the wider farming system (Edwards et al., 1988),fish culture and livestock can improve nutrientrecycling and concentration. This feature isimportant in both nutrient-rich, peri-urban systemsand nutrient-poor, rural situations (Little andEdwards, 1999). Diversity, stability and capacitycan all be enhanced through inclusion of livestock


"A livelihood comprises the capabilities,assets (including both material and social resources) and activities requiredfor a means of living. A livelihood is sustainable when it can cope with andrecover from stresses and shocks andmaintain or enhance its capabilities andassets both now and in the future, while not undermining the naturalresource base".

Source: Carney (1998)

Livelihoods defined

BOX 1.C

Asset pentagon to analyse sustainable rural livelihoods

FIGURE 4

Source: Carney (1998)

Human capital

Human capitalPhysical capital

Financial capital

Social capital

and fish on farms, as can both economic efficiencyand the scope for future change or ‘evolvability’.

The greater ecological similarity of lowexternal input than intensive systems to naturalecosystems reduces adverse environmentalimpacts (Kautsky et al., 1997). But very low inputsystems, especially in nutrient-poor environ-ments, may not adequately support livelihoods,driving poor people to ever more extractive andunsustainable practices off-farm. Small externalnutrient injections may enhance performance orhelp to regenerate degraded agro-ecosystems

(Kessler and Moolhuijzen, 1994). Theproductivity and stability of farming systems inMachakos, Kenya, improved considerably asincomes from off-farm employment werereinvested in agro-forestry, livestock andhorticulture. Intensification of livestock and soilmanagement have also reduced landdegradation in heavily populated parts ofUganda (Lindblade et al., 1998). Integration oflivestock and fish at a community or watershedlevel may have more potential than household-level in some situations.


How the integration of fish culture into small-holder crop/livestock systems affects asset accumulation and livelihoods

Capital Possible impacts of introduction of intensified aquatic resource managementassets Positive Negative

Natural • Reduced pressure on remaining natural •Increased pressure on natural resource stock aquatic resources can relieve pressures for water, nutrients and fish seedon biodiversity and integrity of remaining natural habitats

Social • Increased fish and other aquatic products •Increased discordance on use of resources available for enhancing social relationships within household, increased opportunities

for theft, increased conflicts over water (quantityand quality) available for other purposes

Human • Skills and knowledge developed that •Competition with more vital activities forcan be used to further diversify livelihood time and attentionstrategies •Extra labour burden and change in use of

• Improved nutrition enhances physical nutrient resources could reduce physical and mental health and mental health

Physical • Improved potential for diversification of •Reduced area available for staple cropsfarming systems and livelihoods generally through transformation of land and water holding to reduce risk to both flood and drought

• Physical assets may be multipurpose e.g. for communication and machinery

Financial • Improved overall income and regularity of •High investment cost for pond constructionincome, credit worthiness, and savings may cause indebtedness that poor subsequent

• More diversified production reduces management cannot repayfinancial risk

Framework for role of capital assets in sustainable livelihoods adapted from Scoones (1998) and Carney (1998)

TABLE 1.1


How livestock and fish improve the sustainability of farming systems

System attribute Livestock

TABLE 1.2

Nutrient recycling Feeding crop byproducts such as ricebran and terrestrial and aquaticplants to livestock increases recycling of nutrients within the farm. Pigsare used particularly for this purpose in parts of China and SE Asia

Nutrient concentration Feeding off- and on-farm feeds can allow concentration of nutrients,and act as a pathway for nutrients to be cost -effectively gathered orharvested from common property. Ruminants are important for thisaspect of enhanced sustainability

Diversity Most small-holder farms manage a range of livestock that utilize thevariety of feed resources available. Important advantages include pestcontrol, recycling, manageability, economic reasons (risk aversion andcash flow)

Stability(resistance to change)

Livestock are a stabilizing influence, reducing perturbation onhouseholds during time of physical or social stress. Their variety ofuses (draught, fertilizer, social value, fuel, cash, food) allows small-holders to better maintain productivity when faced with change

Capacity Livestock waste improves soil quality and fertility; grazing can improvespecies richness and reduce soil erosion

Economic efficiency Livestock products are often the major source of cash in small-holdersystems. Having a variety of livestock types improves versatility withrespect to investment, cash flow and risk aversion

Evolvability Dominance of commercial livestock systems threatens the scope forsmall-holder production to change in response to demand


Fish Notes

Nutrients from other sub-systems in the farm are retained infishpond sediments and water and can be used for cropproduction

Use of livestock wastes in fishponds may be the mostpractical way to reduce nutrient losses, especially N

Natural and stocked fish can harvest nutrients from commonproperty for direct human food or use in livestock diets

Overgrazing of common land by ruminants may lead todeterioration, increased erosion and declining sustainabilityof the surrounding watershed or ecosystem

Efficiency of polycultures within aquatic systems in exploitingthe range of aquatic niches. Control of livestock and humanpests with an aquatic phase within the life cycle

Increasing diversity of livestock and fish may complement orcompete within the farming system. Whereas increasedamounts of monogastric waste are valuable for planktivorousfish, grass carp and ruminants may compete for limitedamounts of grass

Maintenance of a water body necessary to raise fishimproves the stability of water availability for the wholefarming system

Livestock can be a contributing factor to destabilization,especially through deforestation, overstocking and soilerosion

Increased water and nutrient holding improves productivecapacity around the pond. Sealing of pond traps nutrientsand prevents loss to ground water

Fertile ponds may not contaminate groundwater significantlybut more research is needed

Small individual size of fish often improves localmarketability. Polyculture and perennial water increasesopportunities for strategic marketing

Returns to labour are often attractive for livestock and fishproduction, and integration is particularly favourable.Integration reduces market risk and improves flexibility

Aquaculture systems are generally recent and are evolvingrapidly around resources and markets. The dominance ofsmall-holder compared to commercial production, andimportance of aquaculture and fisheries as suppliers of fish,are major issues with policy implications

Concept coined by Pullin (1993) to describe the scope forfuture change of any system

1.5.2 MACRO-LEVEL

Sustainability viewed at a macro-level mayinclude global, national, regional and watershedcontexts. The expected dramatic increases inglobal trade following recent WTO agreementsare expected to have wide ranging impacts onthe nature of food production and viability offarming systems. Agribusiness is positive aboutthe effects such measures will have onsustainability of food product (Box 1.D) but othergroups fear a rapid undermining of poorernational economies and marginalization of small-holders with little market leverage.

Global trends in resource use for livestock andfish production, trade and consumption areimportant for understanding constraints at the

farm, or even plot or pond level. One example ofhow macro and micro-level sustainability issuescan interact, and be affected by institutions, is thechanging basis of pig and fish production in theRed River Delta of Northern Viet Nam (Box 1.E).

Pig and poultry production using modernsystems have been challenged as unsustainablein the long term on a global basis because ofdependence on concentrates, which are based onnon-renewable, fossil-fuels (Preston, 1990).Examples exist where modern systems, following‘shocks’, have collapsed. These include oilexporting countries where oil price decline, andassociated revenues made imported con-centrates and poultry production uneconomic.Cuba saw major disruption in its imported,concentrate-based livestock industry as SovietUnion support was withdrawn and favourableterms of trade shifted. Even if concentrate feedscan be used economically, and the wastesproductively reused for aquaculture, there maybe inequities in the system that proveunsustainable in the longer term. Thus, ananalysis of current systems using sustainabilityindicators can lead to the development ofrelevant research agendas. Given its complexity,some advocate the use of consensus indicators ofsustainability in aquaculture production (Caffeyand Kazmierczak, 1998).

The need for alternatives to the narrow rangeof feed ingredients used in most concentrateshas been identified as urgent, especially for thetropics where little research has been conductedso far (Preston, 1990). In China, the substitution ofsemi-intensive aquaculture integrated withinfarming systems by intensive, feedlot productionhas been advocated on the grounds of improvedproductivity and reduced negative environ-mental impacts (Box 1.F). The analysis, thoughflawed, does identify a general tendency towardsintensification of aquaculture. This may haveparticularly large impacts since intensiveaquaculture is relatively more profligate thanlivestock in its use of feed resources and is morepolluting. The major species raised intensively(salmonids and shrimp) are fed diets high infishmeal (Naylor et al., 1999) and often have largeimpacts on the local environment. Potentially theintensification of semi-intensive culture of carps


It is generally accepted that intensification oflivestock and fish production is required as lowproduction levels do not meet people’s needs.The major issue is the level of intensification thatcan support overall sustainable development.

The feed and pharmaceutical industriesmake the following claims:

Aspects of intensification that supportsustainable development:� intensive agriculture allows livelihoods to be

sustained through increased production tosatisfy needs, without the need to furtherencroach on the natural environment withlosses to biodiversity;

� removal of political and trade barriers thatartificially support agriculture and lead toexpensive surpluses:

� high yield agriculture can protect the envi-ronment by reducing soil erosion e.g. use ofminimum tillage, intensified ruminant pro-duction can reduce greenhouse gases, and

� without veterinary medicines, livestock inEurope would need to increase frombetween 25 percent to 89 percent to main-tain existing production levels.

Agribusiness view on sustainability

BOX 1.D

an tilapias will have even greater impacts on theenvironment through raising demand for suchfeeds (Naylor et al., 1999).

Difficulties in maintaining feeds or disposingof wastes will probably be only part of theproblem of sustaining intensive livestock and fishsystems on a macro-level scale. Control ofpathogens may prove a more importantconstraint and pose greater threats to humanpopulations (see 6.1.4). Densities of pigs exceed9000 animals km-2 in parts of Western Europe aseconomies of scale and demand for cheap porkfavour intensified production close toconcentrated markets. The cost of diseaseepidemics such as classical swine fever, and thedifficulties in their control at such levelsof density, are prompting a rethink andnew legislation (MacKenzie, 1998). Similarexperiences are occurring with intensively raised fish such as the Atlantic salmon and blacktiger shrimp. Control of pathogens throughisolation is particularly problematic because of

the need for water exchange in intensivesystems.

High input, export driven agriculture(agronomy, animal husbandry and aquaculture) ismore likely to be non-diverse (monoculture),highly extractive and polluting (little recycling)and unstable in the face of environmentalchange. Moreover, its economic efficiency can bedrastically affected by the vagaries of globalmarkets. Smaller livestock units spread moreevenly, based on local production of feeds anddisposal of wastes, are likely to improve thesustainability of the livestock and associatedfarming systems.

Intensification is important, however, toensure that smaller scale systems are economi-cally viable and sustainable. Improvements inproductivity at the local level have also beenshown to be important globally. Low productiveruminants have been implicated in the increasein greenhouse gases, which could underminesustained food production worldwide (see 4.2.1).


In this region of historically high populationdensity, both traditional farming systems and the‘green revolution’ have failed to sustainlivelihoods alone. Sustainable central and locallevel institutions have been critical to themaintenance of irrigation and flood preventionstructures essential to maintain productivity inthis area characterized by climatic perturbations1.Government policy changes towards a marketsystem with increased availability of inorganicfertilizers, livestock feeds and breeds and fishfarming systems are highly productive, use manyexternal inputs and recycle intensively but recentstudies indicate that sustainability is threatenedby a declining capacity as soils become acidic2.Shortages of organic inputs, and excess inorganicfertilization, may exacerbate these problems.Traditional household pig production is valued forits role in asset accumulation and provision oforganic manure for field crops. Certain

developments may further undermine thesustainability of the system by reducing theavailability of pig manure for application to theland:� Government policy change towards support

for industrial pig production, leading to con-centration of the national herd among fewer,larger producers, and

� increase in aquaculture leading to a demandfor more inputs, including pig manure.

Changes in demand are also occurring:� market for more and leaner pork, increasing

demand for balanced feeds i.e. concentratesand modern strains of pig, and

� increase in demand for tilapia3, which hasbecome dominant in other parts of Asiawhere commercial, feedlot livestock-fishoccurs.

Source: 1Adger (1999); 2Patanothai (1996); 3Binh (1998)

Challenges to sustainable farming in the Red River Delta, Viet Nam

BOX 1.E


Rapid increases in production of culturedfreshwater fish have occurred in China since 1985-86, the time of the Chen et al., study1. Economicgrowth both created demand and the resourcebase to support an estimated 400 percent increasein production between 1985 and 1995. It has beenestimated that by 1996, 40 percent of totalproduction was based on ‘aquafeeds’, completeand incomplete feeds from small and large feedmills2. This infers that the other 60 percent (6.56tonnes) were still dependent on ‘no inputs’ or‘organic farming’. This level of production is nearly250 percent of that recorded in 1985, suggestingthat integrated farming, far from being redundant,has expanded massively.

Since these systems are based primarily onwaste from livestock production, which has alsosoared, any reduction in recycling in fish culturemight further impact the wider environment thatis rapidly deteriorating. Although aquacultureitself is acknowledged as partly responsible forthe general decline in surface water quality thatthreatens further expansion, they2 suggest thattraditional manure-based integrated systems arethe ‘most significant’ contributors. This is at oddswith any other comparison of nutrient accounting

which conclude that in semi-intensive pondculture, most nutrients are retained withinsediments that can be removed occasionally andutilized locally3.

The expected rate of pond expansion2 (1-3percent annually) suggests that even asavailability of improved feeds encourages intensi-fication, semi-intensive practices will dominate inthe foreseeable future. Lack of self-sufficiency infood grains and protein concentrate couldmoderate tendencies towards intensive, feed-only based fish culture systems in China. Demandfor ‘fed’ fish species is increasing rapidly but ofthe major species in the category tilapia, as a filterfeeder, is known to be very cost effectively raisedthrough fertilization and feeding4. Filter feedingcarps still represent 38 percent of totalproduction and registered an annual increase of13 percent in 19962. These levels of growth aremore sustainable than those recorded for highpriced luxury species (>40-80 percent year-1)such as eels and turtles for which markets arequickly saturated and production costs highlysensitive to imported feed ingredients.

Source: 1Chen et al. (1994); 2Cremer et al. (1999); 3Edwards (1993);4Diana et al. (1996)

A decline in integrated farming in China?

BOX 1.F

CHAPTER 2 • EVOLUTIONARY DEVELOPMENT OF INTEGRATED LIVESTOCK-FISH FARMING SYSTEMS IN ASIA 13

Evolutionary Development of Integrated Livestock-FishFarming Systems in Asia

2

Understanding how farming households meet their needs

is essential to assess the likely adoption of fish culture. A study of the evolutionary

development of farming systems provides a useful framework since the nature and

intensity of farming activities may indicate the likelihood of fish culture being

appropriate. We analyse the factors that have stimulated intensification of farming

and relate this to prospects for integration of livestock and fish production.

Agricultural development has been linked to the pressures of human population

growth and we also examine this effect, together with the impacts of changes caused

by urbanization and industrialization.

Systems and scaleA schema of the possible evolutionarydevelopment of integrated farming systems isgiven in Figure 5. Settled agriculture is dividedinto three phases to indicate the potential role ofintegrated farming, particularly with respect tosmallholder farmers in less developed countries(LDCs). Pastoral nomadism and shiftingcultivation have limited aquaculture potential.

Pastoral systems occur in arid regions in whichseasonal availability of grazing limits carryingcapacity of livestock and nomadism is anecessary part of a livelihood strategy. Thismovement of both pastoralists and shiftingcultivators has necessarily constraineddevelopment of fish culture. The limited extentand duration of surface waters in arid regionsalso constrains natural fish production; and fishconsumption is usually unimportant or absentamong peoples living in such areas. Harvestingwild stocks generally remains important foraquatic foods after settled agriculture is well

2.1

developed, whereas hunting and gatheringterrestrial food declines rapidly as agricultureevolves.

The evolutionary development of bothlivestock and fish production can be classifiedwithin a schema derived from the same broaderfarming systems context (Figure 6). Settledagriculture I is typical of many pre-industrialsocieties where there is little integration betweencrops and livestock managed principally fordraught and to meet social obligations. If fishculture occurs it is normally at a very extensivelevel and closely associated with management ofwild fish stocks. In settled agriculture II, theproduction of livestock and crops are moreintimately linked, with livestock fed on crops andcrop by-products and their manure essential formaintaining soil fertility. Use of N fixing plantstogether with other inputs such as nightsoil isalso a common strategy for maintainingproductivity. It is in this context that mosttraditional integrated fish culture is found. Thetrend towards industrial monoculture (settled

agriculture 3) is a model followed by bothlivestock and fish production and is widelyadopted in developed economies. Recentlyhowever, environmental concerns about heavyuse of agrochemicals and waste disposal,consumer pressure and legislation are leading tosome return to a more balanced approach to foodproduction.

The tendency to develop more intensivefarming systems that produce more food per unitarea per unit time has traditionally been linked toincreasing population pressure. Globalpopulation is expected to rise further from thecurrent level of 6 billion, and may double beforestabilizing, even at the most optimisticprojections. Global population is split more or lessequally between urban and rural areas but urbanareas are expected to surpass rural area inpopulation around the year 2005 and to accountfor 60 percent of the total by 2020 (UN, 2000).

Population pressure has not occurred, norexerted its impact on intensification of foodproduction evenly. Historically more fertile, well-


Evolutionary development of integrated farming systems.

FIGURE 5

Source: Modified after Edwards (1997)

Fishing Wildaquatic food

Hunting/gathering Wild terrestrial food

Shifting cultivation

Settled agriculture 1Crop dominated

Pastoral Nomads

Settled agriculture 2 Integrated crop/livestock

Settled agriculture 3 Industrial monoculture

watered environments have had greaterproductive potential and supported higherhuman populations. Thus, well-endowedfloodplain agroecosystems in Asia have becomethe site of the most intensive traditionalagricultural practices. Globalization of trade pre-dating the colonial era, industrialization andmajor changes in human medicine havefundamentally de-linked food production andhuman population densities. If the concept ofagro-climatic population, or the population interms of food production capacity is used, todaysemi-arid zones are typically under much greaterpopulation pressure relative to land endowmentsthan humid areas (Binswanger and Pingali, 1988).Although historically most of Africa has had littlepressure on land resources, by 2025 the majorityof the continent will comprise high-densitycountries requiring highly productive agriculturaltechniques.

Accelerating urbanization has stimulateddemand for industrial food production in both

developing and developed countries. Industrialfood production requires intensive applications ofresources, particularly energy, nutrients andwater and is dependent on scientific knowledge.Farming operations spanning a wide range ofintensity levels can be found increasingly withinthe same country although some doubt thatcoexistence of less intensive production systemswith industrial methods is possible over the longterm. Integration of livestock and fish, in whichone or both sub-systems does not becomeentirely agro-industrially based, may better fit thelimited resource base of smallholders and im-prove environmental sustainability.

Environmental effectsEnvironments have shaped cultures and dietarynorms and taboos that in turn explains current

2.2


Classification of livestock production and relationship to value of livestock wastefor aquaculture

FIGURE 6

SITE

FEEDINGSYSTEM

ENVIRONMENT

LIVESTOCK WASTE VALUE

LOW HIGH

Rural Peri-urban

Grazing/Scavenging

Communal

Grassland Tree crops Field crops Riceland + Wetlands Roughages Crop by

products Grains Concentrates

Individual On farm Off farm

Feedlot

Semi-feedlot

Source: Little and Edwards (1999)

distribution and dependence on livestock andfish. Recent anthropological research has shownthat the concepts of the ‘sacred’ cow and‘abominable’ pig have an environmental basis(Harris, 1997). The advantages of ruminants thatdigest cellulose and thus do not compete for foodwith humans, together with their moremultipurpose attributes, are the bases for thecultural bias. The rejection of fish as food is alsocommon among people in arid environmentswhere surface water and natural stocks ofaquatic animals are rare. The lack of largelivestock in traditional slash and burn-basedsocieties in Africa, and elsewhere, can be relatedto a low requirement for tillage, and their poorsurvival because of the tsetse fly (Binswangerand Pingali, 1988). Animal protein needs could bemet by the harvest of game and wild fish andintensification of livestock and fish productionwas unnecessary (Little and Edwards, 1997) atthe low human population densities found intypical swidden agricultural societies.

If natural supplies of wild stocks areparticularly rich, much higher populationdensities may be supported, provided humandietary energy needs are met. The rice-fishsocieties of lowland Asia are good examples ofthis situation where diets based on cultured,calorie-rich rice were balanced by diverse,aquatic plant and animal food gathered from thefloodplains. Indeed, whilst natural fish suppliesremain adequate, there is little interest in fishculture (Gregory and Guttman, 1996). Seasonalinundation of flood plains that led to dependenceon aquatic-based food sources probably alsolimited the importance of livestock because ofseasonal shortages of feed.

In contrast, arid environments havestimulated pastoral systems in which lowdensities of ruminant livestock are grazed onextensive, common property pastures. Thechallenges associated with increasingproductivity in such marginal, community-basedresources systems are similar in both water-short,livestock-based pastures and water-rich,communally exploited wetlands. Major issuesinclude how intensification can occur whilstsafeguarding equity and the environment (Table 2.1).

Crop dominationIn contrast to most shifting farming, in whichlivestock is relatively unimportant, or pastoralistsin which livestock dominate, animals fulfil smallbut important roles within the household insettled agriculture. Furthermore, settledagriculture has much greater potential foraquaculture. Most land is reserved for crops andlivestock are kept mainly for draught in settledagriculture phase I. Pigs and poultry may also bekept in small numbers, and usually scavenge andare fed wastes from the household. There is littleintegration between crops and livestock, largelybecause the number and nutritional status of thelivestock are low. Ruminants depend mainly onlimited rough grazing of harvested fields andcommon land. Limited crop diversity, as well aslittle recycling of crop residues and manures, arecharacteristics of crop-dominated systems. Suchresource-poverty is typical of most small-scalefarmers in developing countries today, exceptthose that have leap-frogged to settledagriculture III through the green revolution. Crop-dominated systems include crops grown as thedietary staple such as rice and maize, often forsubsistence, together with other crops grown forcash. Various levels of intensification may beevident e.g. irrigation, terracing, fertilization andweeding. Orchard crops and vegetables are oftengrown in home gardens.

In some parts of the developing world, such asSouthern Viet Nam, both livestock and fish arerelatively important even in crop-dominatedlivelihoods (Ogle and Phuc, 1997) but thepotential is far from realised by most householdswhich rely mainly on wild fish. One surveyindicated that farms in Central Thailand, whichhad diversified away from rice monoculture weremore likely to use animal waste for fish culturethan farms continuing to concentrate on riceproduction (Figure 7). Such intensification oflivestock in settled agricultural phase I is oftenlimited by poor feed availability. Also, draughtanimals tend to be used irregularly so althoughtheir productivity is low, farmers have little

2.3


interest in improving their performance. Paralleldevelopment of intensive feedlot operations mayalso reduce opportunities for small-scale pig andpoultry production (Little, 1995).

Widespread adoption of fish culture may nothave occurred within crop-dominated systems,even when fish are valued and consumed. Stocksof wild fish may remain at a level that satisfy ruralpeoples’ needs. Poorly developed on-farm waterstorage, or a lack of seed or knowledge may alsoconstrain adoption. Traditional aquaculture in thevalleys of upland areas of Indochina and SouthernChina, where population densities are high andwild fish stocks are very limited, suggest thataquaculture can evolve under these conditions,but that linkages between livestock and fish wererelatively weak. Intensification of fish productionbased on animal manures would be constrainedby the limited numbers of livestock and


Comparison of common property management and scope for intensificationin water-scarce and flood-prone environments

Environment

Characteristic Water-scarce Flood-prone Notes

Dominant livelihood strategy •Pastoral ruminant production •Aquatic food harvest

Density and yield area-1 •Low •Low

Stock and habitat •Disease control •Maintenance/ •High demand forenhancement •Improved water availability enhancement of habitats indigenous species

•Selective feeding •Stocking of juveniles

Indigenous species •Largely replaced but interest •Typically still dominatein return to ranching though increasingly small,

low value speciesChallenges to sustainability •Overstocking •Over-exploitation

•Range degradation •Siltation

•Irrigation structures and management

Challenges to equity •Herd accumulation by richer •Water extraction forindividuals surrounding agriculture

including aquaculture by richer individuals

•Intensification results in lack of access for the poor

TABLE 2.1

Aquaculture is a recent development amongcertain ethnic minorities, such as the Hmong inupland areas of Indochina, for whom pigproduction is both traditional and important.Under current conditions disease is a greaterconstraint to expansion of pig production thanfeed availability; more arrowroot or cassava canbe grown, or vegetables and banana stems cutfrom the forest, if supplies of maize are limited.Pig wastes are used extensively, withwastewater directed towards opium-poppygrowing plots, but the siting of pens over fishponds has been adopted by some households.

Source: Oparaocha (1997)

Disease constrains livestock production

BOX 2.A


Percentage of farms in Central Thailand using various fertilizer and supplementary feed inputs for fish agro-industry (d) animal by-products and animal feed (e) vegetable matter.

FIGURE 7

20

10

Perc

enta

ge o

f fa

rms

Perc

enta

ge o

f fa

rms

Perc

enta

ge o

f fa

rms

Pig Duck Chicken Buffalo Human

Broken rice Rice bran Milled rice Paddy Maize Cassava Flour

Purchased Domestic Soybean Bread chip Noodle Inferior gradewaste food waste food waste waste processing waste mung bean

(a)

(c)

(b)60

50

40

30

20

10

40

30

20

10


culture (a) manure (b) rice and grain products (c) waste food from human consumption and

50

40

30

20

10

40

30

20

10

Perc

enta

ge o

f fa

rms

Perc

enta

ge o

f fa

rms

Waste Duckweed Water Water Other Grassvegetables spinach hyacinth aquatic weeds

Trash fish Animal Trapped Industrial Concentrateprocessing waste insects feed chicken feed

(e)

(d)

no rice cultivation (n=146) rice cultivation (n=161)

Source: AIT (1983)

difficulties in collection and use of their waste.Livestock diseases also constrain inventories oflivestock in many instances (Box 2.A)

Integrated crop/livestock The integration of livestock with crops, or mixedfarming, is the major characteristic of settledagriculture phase II. Livestock fed arable cropsand improved pasture produced on the farm isthe main focus. Crops are intimately integratedwith livestock as manures are used to maintainsoil fertility together with N fixing legumes.Much of the farming in Western Europe andEastern USA was of this type between 1850-1945.However, the recent increased control of nutrienteffluents has begun to favour this form of farmingagain over industrial monoculture.

The origins of mixed farming lie in increaseddemand for livestock products from urbancentres. Various methods were adopted toincrease livestock such as production and

feeding of turnips to livestock during the winterand the rotation of cereal crops with legumessuch as clover. More inputs such as nightsoilfrom urban centres, followed by inorganicfertilizers and feed concentrates, increasedlivestock densities and soil fertility.

Integration of fish culture into farmingsystems has developed in areas where pondswere essential to diversification of rice-dominantsystems and livestock were relatively few andfeed limited. This has occurred in flood-proneareas, often where rice yields were low (Ruddleand Zhong, 1988) and land was raised to makedikes for planting perennial or upland crops.Increasingly, buildings and roads are constructedon raised dikes and fill is obtained from borrowpits. The ponds excavated often serve primarilyfor storing water on-farm. Expansion of on-farmreservoirs (OFRs) has also expanded in areas inwhich drought otherwise constrained any inten-sification of cropping.

Analysis of traditional integration of fishproduction within the highly diversified farms inthe Zhujiang Delta, Southern China, indicatesthat wastes from livestock (pigs, silkworms) and

2.4


Small flocks of mixed poultry, allowed to scavenge for natural feed and given small amounts of supplementaryfeed such as paddy grain or ricebran, are common in Asia

people were important inputs. Fish production,however, was mainly based on the feeding ofwild, uncultivated grasses for the macrophagousgrass carp. This fish species largely filled theniche occupied by ruminants in mixed farmingsystems in Europe. Recently other macrophagousfish species such as the silver barb have beenpromoted to utilise seasonally abundantduckweed in Bangladesh (Morrice, 1998). Thefeeding of leafy vegetable material is traditionalfor raising macrophagous giant gourami inIndonesia, and potential exists for similarsystems elsewhere based on herbivorous tilapiasand Colossoma spp.

The major constraint to fish culture withinfarming systems based on leafy vegetation is theavailability of adequate amounts to meet theneeds of growing fish. Constraints to, andopportunities for, intensification of macropha-gous fish production are similar to ruminants(Box 2.B). Opportunistic use of crop harvest by-products would not normally provide consistentlevels of feed or feed quality. Continuous

cropping of arable crops, e.g. cassava leaves hastrade-offs in terms of the main crop yield. The useof arable weeds from intensive horticulture hasunrealised potential in some situations (Moody,1995) but would normally be constrained byirregularity of supply. Where such products areavailable, there will usually be competition withlivestock.

Industrial monocultureMany ‘modern’ settled agricultural farms stages Iand II have intensified production by adoptingsome aspects of the scientific-industrial‘revolution’. Industrial monoculture (settledagriculture phase III) has evolved to supply everlarger, more concentrated markets withhomogenous products. Increasingly dependenton the fruits of science and engineering,traditional mixed farming has changed over thelast fifty years, using a greater range and volume of inputs. Improved varieties, agriculturalchemicals, feeds and mechanization are used toproduce fewer products in greater volume; manyfarm operations have become monocultures. Thetechnical complexity and economies of scalecharacteristic of industrial agriculture encouragethis tendency. In most cases the readyavailability and low cost of industrial nutrientshas reduced the need for integrating crop andlivestock production. Industrial aquaculture,often of carnivorous species, evolved from usinglocal surpluses of trash fish of little value to fattenwild fish and there were few links with land-based agriculture.

Two important reasons suggest thatindustrial monoculture will evolve towardsgreater integration with other food production.Firstly, the real costs of adverse environmentalimpacts of specialized production are nowbecoming clear and closer integration can reduceor eliminate them. Secondly, wastes fromintensive animal production can be valuableinputs into other parts of the farming system.

2.5


� Consistent quality and quantity of greenfodder required to match needs of growingstock

� Seasonality of availability

� Harvest by-products often useful only as anoccasional supplement

� Trade-offs in regular harvest of greenleaves from growing crops

� Development of ‘cut and carry’, in whichintensively grown vegetation that can becut regularly and grows back rapidly, is amajor step and requires significant land andlabour resources

� Key factor is the value of livestock and fishproducts relative to resources such as landand labour

Intensification of ruminant andmacrophagous fish have similarconstraints

BOX 2.B

Apart from maintaining soil structure in arablesystems, these include their direct and indirectuse in fish production.

In parts of Asia where concepts of wasterecycling are traditional and well understood, theindustrialization of agriculture and changingdemand are both challenging and opening newpossibilities for integration. On the one handintegrated livestock-fish systems are evolving inChina to rely increasingly on wastes from non-traditional livestock such as dairy cows andbroiler chickens. Livestock wastes are also beingused for a greater range of purposes; mushroom,maggot or earthworm production may be moreprofitable than aquaculture (Wang, 1994).However, rapid industrialization and movestowards intensive aquaculture practices can alsoundermine traditional integrated practices andthreaten ecological stability.


CHAPTER 3 • MAJOR TYPES OF INTEGRATED SYSTEMS IN ASIA 23

Major Types of IntegratedSystems in Asia

3

The role of livestock in the intensive, rice-based farming

systems on the major floodplains of China, where aquaculture first developed, was

fairly minor and linkages between fish and livestock production correspondingly

weak. Applying the principles of waste recycling was, however, integral to sustaining

China’s high population densities. In recent decades, as the importance and

concentration of livestock and their wastes have increased, these ideas have been

applied more widely in China and elsewhere in Asia to reuse livestock waste for fish

production. A range of experience and systems now exist.

The growth in production of monogastriclivestock and agribusiness concerns has had amajor impact on availability of waste foraquaculture. It has also changed the manner inwhich livestock are raised and marketed. Lowerpriced livestock products are the result but mostare produced by entrepreneurs. Small-holderfarmers have often benefited least.

Attempts to scale-down commerciallivestock-fish systems for resource-poorerfarmers have been uneven because of difficultiesof access to, and management of, inputs such asfeed and outputs. Alternative livestock systemsthat produce waste suitable for fish culture are

still largely undeveloped. Typical smallholder,ruminant and monogastric production isextensive, making wastes difficult to collect anduse. The wastes from poorly fed animals are oftenlow quality. Upgrading such livestock systemscan increase the potential for integration withfish culture. Strategic intensification andintegration of livestock and fish are alternativeparadigms to the conventional models ofagribusiness development. Improved efficiencyof nutrient use under conditions of nutrientscarcity can be a major benefit of integration.Least-cost production techniques that dependon using several different fertilizers and feeds,


rather than a single high-cost compounded feed,is a relevant strategy for both livestock and fishproduction.

Commercial livestock production andprocessing typically produce nutrients inabundance, requiring cost-efficient disposal.This offers a different but equally importantrationale for integration.

Current status3.1.1 GENERAL CONSIDERATIONS

Livestock-fish systems in which waste fromanimals continuously raised in a pen and fedcomplete feeds (‘feedlot’) are used as pondfertilizers are the most common type ofintegrated system outside China (Edwards,1993). Important characteristics used to classifysuch systems include type of livestock and fishspecies and scale of operation. The degree ofintegration has already been raised in definitionsof integrated farming (Chapter 1). Definitions caninclude whether the fish sub-system receives allthe livestock wastes, if livestock waste is used as

a single input or as part of a multiple-inputsystem. Since fish production is closely linked tothe quality and quantity of inputs, the nutritionalvalue of specific livestock wastes, in fresh orprocessed form, is also an important descriptor.

The major types of livestock may beclassified on their potential for integration withfish culture (Table 3.1). Most fish productiondata for culture systems fertilized with livestockmanure are based on feedlot systems but wastesfrom animals raised in scavenging systems canalso be used. Clearly the latter waste is less easyto collect than waste from animals confinedcontinuously. Some livestock wastes are moreacceptable than others; whereas poultry manurefrom broiler houses is easy to handle and is usedwidely in agriculture, pig manure is often lessacceptable for logistic, religious or aestheticreasons. This is also reflected in opportunitycosts. These may be relatively high for driedpoultry waste and low for pig and cattle slurry.Nutrient density is also an important factor asmonogastric animals fed high-quality feeds tendto have manure that is more nutrient dense andvaluable than ruminants, particularly thoseraised on nutrient-poor tropical volunteervegetation.

3.1

Matrix of livestock waste qualities and suitability for use in aquaculture

Factors increasing relative suitability for aquaculture

Livestock type Collectability Acceptability Nutrient Low Lack ofdensity opportunity deleterious

cost compounds

PoultryFeedlot *** *** *** * ***Scavenging * ** ** ** **

PigsFeedlot *** * ** ** ***Scavenging * * * ** **

RuminantsFeedlot *** ** ** ** **Scavenging * ** * ** *

(*** = high to * = low)Source: Little and Satapornvanit (1997)

TABLE 3.1

Some animal manures contain compoundsthat cause water quality problems, such astannins and indigestible fractions. Waste fromanimals receiving poor nutrition, especially thoseon diets with high levels of fibre, is particularlyunsuitable for fish culture. Other wastes may becontaminated with deleterious compounds suchas pesticides, drugs or feed residues that havenegative impacts on quality (Table 3.1).

3.1.2 MONOGASTRICSStatusMost integrated livestock-fish systems describedin the literature and operating successfullyinvolve the use of manure from feedlotmonogastrics. Pig and poultry manure is usedfresh, or commonly for poultry, in a dried form forsemi-intensive fish culture. Design criteria aregiven below (Chapter 5).

PigsNative varieties of pigs are well adapted toexisting on roots, leafy vegetables, cereal by-products and household food waste (Livingstoneand Fowler, 1984). Although they are notruminants, fermentation in the hind gut issignificant and this allows them to grow slowlyon a poor diet. An important food item in somecultures is human waste, scavenging pigsplaying an important role in nightsoil disposal.

In some cases intensification has been builtaround waste recycling. Traditional pigproduction in China was mainly for theproduction of manure (Ruddle and Zhong, 1988)as is still the case in northern Viet Nam. Weanedpiglets are traditionally fattened on considerablequantities of grain by-products or root crops,especially sweet potato (Ipomoea batatas)supplemented with cultivated and volunteergreen fodder. The number of animals raised istherefore related to the production andavailability of these feeds, and the number raisedper household is low. Pig manure was used tofertilize rice and vegetables, which may explainwhy the average fish yields in China were as lowas only 2 tonnes. ha-1 until as recently as twodecades ago, before more widespreadintroduction of feedlot livestock-fish integration.

Fish culture in northern Viet Nam is similarlyconstrained by the competing use of pig manureto fertilize crops.

PoultryLocal breeds of poultry can thrive inenvironments with abundant natural feeds,which are often rich in calcium and animalprotein. Ducks are particularly important in theflooded agroecosystems of South Kalimantan andSouthern Viet Nam, and in Java where irrigationsupports year-round, paddy rice production.Management has become more intensive inmany cases. It involves the confinement ofpoultry (and pigs) for all or prolonged periods toensure both adequate nutrition and production,


In Pathum Thani, Central Thailand, a peri-urban area outside the main industrial belt atthe time of the survey in 1980, there was aclear dichotomy of monogastric productionsystems. Farmers were more likely to havesmall flocks of chickens (>60 percent offarmers) or ducks (>30 percent) than pigs (<15percent) (Figure 8).

Both the species and scale of productionwere found to affect the likelihood of theirintegration with fish culture in the province.Whereas farmers raising pigs were likely tointegrate them with fish culture across a rangeof herd sizes, only farmers with large flocks ofeither ducks or chickens tended to use theirwaste for on-farm fish culture. Generally pigherds of less than 30 animals were less likely tobe integrated with fish than those of more than30. Pigs raised in large and small units weresimilar improved strains, fed and managed infeedlots. In contrast, large flocks of poultry,which were confined throughout their short,well-fed lives, were improved strains and smallflocks managed extensively tended to be localbreeds.

Source: AIT (1983)

Case study of integrated farmingin Central Thailand

BOX 3.A


and control damage that freely scavenginganimals can inflict on crops.

Poultry are also raised in large numbers whenlocal or seasonal food surpluses occur. Anabundance of aquatic snails from the lakeallowed duck producers to intensify balut duckegg production in Laguna, Philippines, beforefeed mill-based feeds were available. Meat ducksare purchased and raised for short periods inlarge quantities to grow on dropped grain inricefields after the rice harvest in CentralThailand during which time there is littleopportunity for waste collection. But prior toslaughter the ducks are fattened intensively athigh density producing large amounts of highquality, easily collected waste that is used for fishculture.

Failure of scaled-down modern systems integrated with aquacultureSmall-scale, feedlot monogastric-fish systemshave been shown to be technically viable in on-station and researcher-managed, on-farm trials.However sustained adoption of these types ofsystems by farmers has been rare. Almost allresearch has been carried out using waste from

‘improved’ livestock systems, typically feedlotproduction of pigs and poultry. Such research hasnormally been carried out without participationof farmers in the design stage and, often, withfinancial incentives to encourage collaboration.

The normal criteria used for assessment of‘viability’ are positive internal rates of return, orreturn to labour or capital. However, these are notholistic enough indicators, given the complexityof small-scale farmers’ livelihoods. Resource-poorfarmers have great difficulty sustaining evenscaled-down, feedlot integrated systems. InThailand it was found that production costs,particularly feed costs were high and there wereproblems in both securing inputs and marketingproduce in rural areas. In effect, integration offeedlot livestock and fish for most small-scalefarmers is a ‘technological mismatch’ (Edwards,1998). A recent review of similar, small-scale, eggduck production systems in the same regionfound that with improved infrastructure, accessto feeds and markets had improved. However,farmers still tended to either extensify productionby reducing feed concentrate and allowingdaytime scavenging or consolidate larger flocksto ensure viable returns (Box 3.B).

Meat ducks herded through rice fields after harvest being transported for fattening on an integrated fish farm


FIGURE 8Pe

rcen

tage

of

farm

s

Source: AIT (1983)

Livestock present ( ) and integrated ( ) on fish farms in Central Thailand by typeand number of livestock.

1-10 11-20 21-30 31-40 41-50 51-100 101-200 201-300 301-400 >400Number of animals

1-10 11-20 21-30 31-40 41-50 51-100 101-200 201-300 301-400 >400Number of animals

1-10 11-20 21-30 31-40 41-50 51-100 101-200 201-300 301-400 401-500 >500Number of animals

40

30

20

10

(a)

Perc

enta

ge o

f fa

rms

40

30

20

10

Perc

enta

ge o

f fa

rms

40

30

20

10

(c)

(b)

PIGS

DUCKS

CHICKENS

Small is a relative term for both fish andlivestock production. A profitable layer chicken-fish system was described in one area ofNortheast Thailand (Engle and Skladany, 1992).Although farm size was within the norm for theregion, operations tended to be irrigated and

highly capitalized compared with typical, rain-fed farms in the same area. The concentration ofoperations close to a provincial urban centre alsofavoured the provision of cost-effective inputsand sale of produce, and the scale of operationswas advantageous to both farmers andmiddlemen (Engle and Skladany, 1992).

The introduction of new types of livestockwithout consideration of markets has beenanother cause of failure in livestock-fish systems.Cattle and broiler chicken production were‘stand-alone' enterprises in Panama beforefishponds were introduced, whereas pigs andducks were introduced with the fish (Lovshin etal., 2000). The latter subsequently sufferedmarketing problems because of low demand,which consequently had an inverse impact onfish yields as there were insufficient livestock tofertilize the ponds. Similar problems have beenreported in various African countries where meat


The small size of backyard poultry flocksconfined overnight for manure collection limitstheir impact in even a small fishpond. Moreover,variations in flock size and structure greatlyaffect actual waste availability through theyear. Increasing flock size so that more waste isavailable for fertilizing fishponds requiresimproved availability of supplementary feedand a reduction in mortalities, particularlyamong young poultry.

The sustainability of traditional livestockproduction, especially of pigs and poultry thatrequire grain and/or grain by-products issensitive to the availability of these inputs andmarkets. Commercial, vertical integration offeedlot livestock using improved breeds andformulated feeds, whilst leading toopportunities for large-scale feedlot livestock-fish culture, may compete for the feeds andmarkets of backyard pig and poultry producers,reducing their economic viability.

Traditional management of monogastricshas relied on their ability to scavenge food fromaround the household and the widerenvironment. Generally, although local strainsof livestock produce less meat or eggs from thesame quantities of feed than modern breeds,they can survive and convert the poorer qualityand variable quantities of supplementary feedtypically available to smallholders. However,the practical difficulties of collecting wastesfrom unconfined animals and the lowerquantities and quality of manures produced,has constrained attempts to integrate suchsystems with aquaculture.

Constraints to integration of traditional livestock and fish production

BOX 3.B

This woman has few chickens herself but collectspoultry manure for use in fish culture from a neigh-bour house


ducks were introduced specifically to providemanure to fertilize fishponds without dueattention to the wider system.

3.1.3 RUMINANTS

Ruminant faecal waste is probably the mostcommonly used fish pond input in developingcountries. In addition to its use in fish culturebeing limited by competition as a crop fertilizer orfuel, it has an inherent poor quality as a pondinput. Wastes from unimproved grazing animalsmay be too poor in quality to produce acceptablefish yields in small ponds. In an on-farm trial,around 4 tonnes of fresh ruminant manure had tobe collected and used to produce only about 20kg of fish in a backyard 200 m2 pond (Shevgoor etal., 1994). The buffalo manure had low N and Pcontents and also contained tannins whichstained pond water brown, further limitingphytoplankton growth due to reduced lightpenetration into the water column. Tannins arealso known to be toxic to tilapias (Saha andKaviraj, 1996).

A further major constraint is the collection andtransport of low-value, bulky ruminant manures.

Fish culture, however, may be integrated withtraditional livestock management practices throughlinking the needs of livestock for watering,wallowing or overnight corralling. The need tohandle and move bulky ruminant manure may thusbe negated by strategic husbandry practices.Communal or individually-owned water bodiesdesigned to allow the walk-in entry of largeruminants without physical destruction ofembankments can allow low-cost ruminant wasteinput as well as conservation and concentration ofnutrients from the watershed as a whole. Temporaryovernight corralling and/or midday wallowing forwater buffaloes in small areas may furtherconcentrate wastes. Farmers can therefore ‘harvest’nutrients from their own and others livestock at littlecost. The relationship between herders and cropgrowers in West Africa in which livestock are rentedto deposit dung overnight in an area to be planted tocrops gives a working example how manure couldbe managed in fish culture. In NorthwestBangladesh, the overnight tethering andsupplementary feeding of cattle around the houseallows drainage of urine into nearby borrow pits,enhancing the productivity of an important sourceof fish consumed by the household.

Golden Apple snail (Pomacea canaliculata) is a pest in ricefields in the Asian Region but has been used as feedfor poultry, pigs and catfish


3.1.4 NON-CONVENTIONAL LIVESTOCK

Non-conventional livestock encompasses both‘micro-livestock’, a term coined for species thatare inherently small and seldom considered in thebroader picture of livestock development (NRC,1991) and invertebrates, which may be producedas either direct food items for humans orconstitute part of the diet of other livestock orfish. Over 40 multipurpose species with promisefor smallholders were identified in an exerciseinvolving 300 animal scientists in 80 countries.Many will produce wastes that can be readilycollected because of their small size andconfinement during production and are suitablefor aquaculture.

Small individual size, and limited demands forfood and space make micro-livestockincreasingly attractive to resource-poor people.Micro-livestock, including both rare breeds ofdomesticated species and wild animals withpotential for domestication, often retain local

importance to small-holder families and havepotential for larger markets, especially in culturesthat value wild or bush meat.

Non-conventional livestock that can growand reproduce on feeds that do not compete withhuman or other livestock are particularlyinteresting. Some invertebrates can be includedin this category and are locally important assources of food and fibre.

Pasture/crop by-product fedThese include geese and rabbits for direct humanconsumption; and silkworms which are mainlyraised to produce high value, natural silk fibre.Geese and rabbits have played important roles insmall-holder systems in which pasture and fieldcrop by-products are available. Silkworms havebeen an important component of small-scalefarms in parts of Asia for millennia.

The high intake, poor digestion strategy ofgeese means that their manures would probablyfunction in a similar way to that of the grasscarp in fishponds. In contrast, the copraphagy of

ABOVE

Rabbits and guinea pigs fertilizing fishponds inNortheast Thailand

RIGHT

Moina, the water flea, commonly used to raise juve-nile fish intensively can be produced in earthen orconcrete ponds on a variety of livestock wastes andinorganic fertilizers


the rabbit may reduce nutrient levels of theirmanure; rabbit manure, however, is widelyprized as a fertilizer and has been found to be auseful fish pond input in Africa (Breine et al.,1996).

Woody wasteTermites are some of the most commonly usedfeeds in recently developed smallholdersfishponds in parts of Southeast Asia. However,unsustainable harvesting of wild moundsnormally quickly eliminates this potentiallyimportant food source as its rate of regenerationis usually far too low to permit even medium termuse. However in Ghana, harvesting of termites forpoultry is carried out sustainably by placingmoist cow dung over termite nests shielded withtins. The termites burrow into the dung and somecan then be fed to the chickens daily (NRC, 1991).Although actual quantities are small, termites arehigh quality feeds for a range of fish species andpoultry. Where woody waste is produced in largeamounts, their controlled production is apossibility.

Upgrading traditional livestock systems for aquacultureChanges in traditional livestock systems havedirect implications for peoples’ welfare,biodiversity and the wider environment. Theplace of livestock within farming systems hasalways been dynamic and, particularly inmarginal environments, reflected the resourcebase. Intensification of animal production hasoften been a critical part of improving rurallivelihoods generally and a key issue is whetherupgrading of livestock can become a key part inpromotion of rural aquaculture.

‘Upgrading’ suggests an increase inproductivity and importance of the animal withinthe farmer’s system; normally genetic andmanagement changes may constitute upgrading.Changes in germplasm alone rarely support long-term change.

3.2

Sericulture produces several by-products that can be used as inputs for aquaculture

3.2.1 UPGRADING LIVESTOCKDIETS AND PRODUCTION SYSTEMS

The upgrading of livestock systems in developingcountries has often resulted in a total loss oftraditional breeds and management methods. Afocus on improving yields rather than meetingthe needs of the farmers and consumers has oftenbeen counterproductive in Least DevelopedCountries. Typically efforts have been made todevelop a modern poultry industry in parts ofAfrica, whilst smallholder production has beenlargely ignored. However, improvedmanagement, disease control and strategicsupplementary feeding can vastly improveproductivity (Box 3.D).

Sometimes upgrading has occurred inresponse to markets or demand changes; thepoorer meat quality and body shape/sizehastened the decline of the indigenous Mongkonpig in Viet Nam despite their advantages interms of tolerance to heat and low input diets.

Farmers also prefer modern breeds because theygrow faster whether fed traditionally, as innorthern Viet Nam, or mainly on formulated feedin the south of the country. There has often beena failure to fully understand the complex role oftraditional livestock production in rurallivelihoods. After the purposeful destruction ofthe native creole pigs in Haiti because of fears oftheir possible role in transferring African swinefever to North America, modern breeds of pigfailed to meet small-scale farmers’ needs and asynthetic version of the traditional breed had tobe ‘reinvented’ (MacKenzie, 1993).

Livestock systems, however, generally haveto be improved in terms of the collection andquality of waste for productive integration withaquaculture. In practice, livestock manure fromunimproved systems may be too small inquantity, too poor in quality, or simply unavailablebecause of competition from alternative uses, tobe of relevance for aquaculture. Wherelivestock/crop interactions are already underthreat, for example in Nepal, sustainability ofcrop yields are already dropping because ofintensified practices and declines in livestock. Incontrast, increased demand for milk andintensified cropping of a fodder crop rotated withcereals is leading to more livestock and greatersustainability in the Punjab (Fujisaka, 1995).

The quality and quantity of wastes areinfluenced by the diet and other factors (Chapter5). The collectability of livestock wastes dependson feeding and housing arrangements. Clearly,waste can be collected more fully and efficientlyin animals confined for all or most of theproduction cycle. However, larger numbers ofanimals raised more extensively, but confined forpart of the production cycle, can also producesubstantial quantities of waste. Moreover ifquantity and quality of feed consumed during theperiod of grazing/scavenging are high, this isreflected in the quality of the waste.

Several factors mitigate against the ability ofsmallholders to increase number, confine andfeed livestock enough to benefit from using theirwaste for fish culture. The limited ability ofmonogastrics to utilize diets high in fibre hasreduced the scope of improvements to traditional


� Can the resource base support improvedfeeds and feeding strategies?

� What consequences do new, on-farm feedshave for the current farming system?

� Do introduced strains thrive under the production conditions?

� What are the consequences for maintaininganimal health? Is veterinary support avail-able?

� What is the likely demand for more animalproducts with the same or different characterisitics?

� Will upgrading management allow wastecollection and use in aquaculture and doesthis negatively impact on current methods?

� What are the disadvantages and risks inherent with ‘upgrading’?

Key indicators of the potential forupgrading

BOX 3.C

systems of raising pigs and poultry. The numberof monogastrics that could be raised has beenlinked to the availability of grains and/or rootcrops surplus to direct human consumptionneeds. The processing of staple foods such asmaize and rice within the household has been acritical source of brans and broken grainssuitable for feeding livestock in traditionalsystems. Commercialization of food productionthat leads to processing grain off-farm leads tolosses in opportunities for small-scale livestock,unless a concomitant increase in fodder cropproduction occurs.

Recent research with farmers has identifiedpromising strategies for breaking this

dependence by using feed inputs available on-farm such as sugar cane as energy sources(Preston, 1990). High quality forages such asmulberry, hibiscus and cassava leaves canprovide some or all of the protein needed intropical livestock systems (FAO, 1999a) but formonogastrics suitable protein sources mayultimately constrain such systems (Kroeske,1972). Soybean fodder and small fish have beenused successfully for pig production in the fewcases in which these are available. The ability ofducks to utilize low-fibrous plant material such asduckweed has also been shown.

Small-scale farmers may have a continuedrelative advantage in the production of ruminantsand village poultry because of their forage-feeding base and special characteristics (taste,texture, ‘organic' origin). Non-conventionallivestock that can be reared to substitute forforest or bush meat may fill a similar niche that isexpanding in many places where industrial foodproduction is becoming the norm. In general,however, these systems must be upgraded to alevel of productivity that meets the farmers'rising expectations. Clearly, some degree ofintensification of livestock is necessary for anyintegration with fish culture to be sustainable.Market development and veterinary support,however, are often critical to the development ofsuch improved systems.

3.2.2 COLLECTION OF MONOGASTRIC WASTES IN SMALL-HOLDER SYSTEMS

The adoption of semi-feedlot systems withcontrolled grazing/browsing for part of the dayand confinement with supplementary feeding forthe remainder of the day and night-time mayhave the greatest potential for upgradinglivestock production and allowing integrationwith aquaculture by small-holders (Figure 6). Thiscombines the low-risk advantages of traditionalsystems with enhanced productivity producingmore and better quality livestock waste that canbe collected for use in fish culture. Aquaculturecan, therefore, become a focus for improvingoverall nutrient use on-farm. The nutrient-poor


More than 60 percent of rural families in theEthiopian highlands keep chickens and womenown and manage the birds and control the cashfrom sales. Average egg production ofscavenging hens is around 40 eggs bird-1 year-1.In a trial with a women’s group, it was foundthat improved housing and management suchas provision of water, removal of eggs andprevention of broodiness improved productionto over 100 eggs bird-1 year-1. These resultswere obtained using the local strain of henvaccinated against Newcastle disease. Supple-mentation with maize only, noug cake (a locallyavailable protein-rich oil cake) only, or the twofeeds combined increased yields to more than200 eggs bird-1 year-1. The highest productionwas obtained on the maize only diet, confirmingthat the scavenging chickens were limited moreby lack of energy than by protein. Thisapproach to upgrading scavenging chickens canincrease the returns from this activity and, asboth flock size and plane of nutrition isenhanced, increase the amount and quality ofcollectable wastes for aquaculture.

Source: Dessie and Ogle (1996)

Upgrading scavenging poultrydiets and management in Ethiopia

BOX 3.D


status of small-scale farms contrasts with thehigh losses of nutrients, particularly N, whichoccurs before collection and reuse. The N frombackyard poultry waste and urine from ruminantsis often almost completely lost. Whole-farmstrategies that incorporate fish culture mayenhance conservation and recycling of thesenutrients, particularly if livestock are raised inimproved, semi-feedlot systems. Such systemsmay also favour the strategic import and use ofnutrients as feeds or fertilizers on to the farm.However, substantial and cost-effective improve-ments in productivity of the whole systemprobably require both better recycling and use ofmore inputs.

A major problem with upgrading scavengingpoultry flocks to a size that their manure can havean impact on fish production is poor survival ofstarter birds, and poor availability and/or cost ofsupplementary feed for growing birds. Thestrategic use of higher quality feed for startersand use of alternative supplementary feed foradults can increase flock size, and quantities andqualities of waste available (Khalil, 1989). Theadoption of heat stable vaccines to preventNewcastle’s disease has had a major impact inareas where available (Alders and Spradbrow,2000). The collection of waste from scavengingpoultry overnight is often possible even when

they remain unconfined; roosting of birds overponds can be encouraged with strategic feedingand placement of perches/cover. Manure caneven be collected under tree branches or withinhousing by placing sheeting under roostingpositions and feeding stations. The sheets, whichcan be old textile material or split fertilizer bagscan then be washed or suspended in thefishpond.

3.2.3 RUMINANT SYSTEMS

Inadequate feeds and their poor utilization arekey constraints to improved ruminant systems.The greater use of crop by-products,undergrowth of tree crops and improved fodders,particularly legumes, have been promoted to, andadopted by, farmers. The three strata foragesystem in which grasses and ground legumes(first stratum), shrub legumes (second stratum)and fodder tress (third stratum) allows goodquality feed to be produced year-round in drylandfarming areas of Bali (Devendra, 1995). Theintroduction of multi-tiered feeding andpolyculture in these terrestrial agroecosystems isanalogous to the multiple feed/space nichestypical of fertilized fish ponds stocked with apolyculture of fish.

The use of supplementary concentrates such

Making pig feeds in southern Viet Nam using local resources by cooking village rice bran and water hyacinthtogether


as ricebran can further improve performance,especially of pregnant and lactating animals. Thebiggest challenge is to improve the feeding valueof the large amounts of fibre (ligno-cellulose)available. The use of pretreatment using alkali orurea, which improves fibrous feed quality, hasbeen promoted but is not widely adopted byfarmers, except in China where it has beensuccessful (FAO, 1997). Although the use of mult-inutritional blocks, providing nitrogen and micro-nutrients, are being used in several countries toimprove the utilization of low quality feeds (Lenget al., 1991), in practice their use is oftenconstrained by their poor availability to farmersin rural areas (Peacock, 1996).

Improved feeding often develops withincreased confinement of ruminants on small-scale farms in Asia. Animals that are stalled someor all of the time, and fed cut-and-carried foragesand/or concentrates, tend to show increased

productivity and produce wastes of higherquality and collectability (Chapter 5).

Both low nutrient density and highconcentration of tannins negatively affect waterquality and limit the amount of faecal wastes thatcan be used in fish culture. An optimal strategyunder many conditions would be to use solidwastes to fertilize crops and to collect urine andwashing water for fish culture. Normally,collection and retention of urine N in the farmingsystem is problematic. Generally the urine simplysoaks away or is absorbed by bedding and solidfaecal waste. Use of greater quantities of beddingmaterials high in carbon (C), such as straw orstover, improves N conservation but these maybe unavailable in the quantities required.Nitrogen is also lost or becomes refractory undersuch conditions (Anderson, 1987). Pens can beconstructed with a thin sloping concrete floor todirect urine and washing water into a plastic bag.

ABOVE

Herding ducks in the Red River Delta. Overnight confinement and supplementary feeding allows collection of wastes for use in fish culture

RIGHT

Washing a plastic sheet placed to collect manure andwaste feed from scavenging ducks penned overnight


Where concrete is unavailable, elevated woodenpens, which are often used for stalling smallruminants, can be sited directly over the pond. Inpractice, however, livestock are often pennedaway from the pond and waste has to becollected and carried. There is a need to developpractical methods to collect urine, perhaps usingsimple plastic sheeting and bags.

3.2.4 MIXED INPUT SYSTEMS

In many situations livestock wastes will be onlyone of several nutrient inputs used to raise fish.Livestock wastes may be too few, low quality oravailable irregularly. Multiple inputs are used inboth subsistence and commercial fish culturewith livestock waste to capitalise on anoccasional or seasonal abundance of otherwastes and by-products and to improve theoverall balance of inputs into the pond.

The use of multiple inputs usually suggeststhat livestock production does not dominate fisheconomically. Use of livestock manure aloneusually suggest that aquaculture is a relativelyminor component of the overall system.

SmallholdersVarious factors may limit the number of livestockthat a farmer can manage and integrate with fishculture, reducing wastes to levels belowoptimum. Edwards et al. (1983) found thatproblems marketing duck eggs, and high feedcosts, constrained small-scale farmers maintain-

ing even 30 ducks over small ponds (200 m2) asfeedlots. Farmers with limited numbers of poultryfor their pond area need additional nutrientinputs to optimize productivity. Extension ofmultiple input systems can increase overall levelsof inputs used by small-scale farmers, althoughoften not to the levels considered optimal byresearchers (Thu and Demaine, 1994; Ahmed etal., 1995; AASP, 1996). In a project in Bangladeshthe frequency of poultry waste used as pondinputs increased from only 3 percent of farmers tonearly 30 percent after extension (Table 3.2).Comparative figures for cattle manure, inorganicfertilizer and rice bran reflected higher initial use.

Supplementing low-nutrient density wastesfrom scavenging animals with other inputs isparticularly common. Farmers in Udorn Thani,Thailand used a variety of inputs, in addition tolivestock manures including a variety of plantleaves, and rice bran (AASP, 1996). The wastescollected from limited numbers of scavengingducks fed a supplement at night can increase fishyields in systems fertilized inorganically by over40 percent. Additionally, the overall efficiency ofthe limited ricebran used on the farm is improvedand products diversified (Table 3.3). In smallponds, the relative amounts required are alsoaffordable, given the value of the fish produced(Edwards, 1996).

Change in frequency of pond inputs before and after extension in Kapasia Thana, Gazipur District,Bangladesh

Input type Percentage of householdsBefore After

Cattle manure 66 100Inorganic fertilizer 29 100Rice bran 48 100Poultry manure 3 29

Source: Modified after Ahmed and Saha (1996)

TABLE 3.2

Use of wastes from ducks fed supplementary food, in addition to inorganic fertilizationd

Yieldb Food Fish Duck eggs Conversion(kg) (No.) Ratioc

Ducks onlya - 300 5.5

Fish only 45 - -

Fish + Ducks 65 300 3.2Source: Little and Edwards (1999)

a Duck wastes include all wastes (excreta plus waste feed).b net fish yield for a 330 m2 earthen pond over a 90-day period,

extrapolated from fish growth in 5 m2 tanks.c Food conversion ratio of fresh village ricebran to weight of eggs

produced from a flock of 15 muscovy ducks (4:1 female:male).d Inorganic fertilization at 3 kg nitrogen ha-1day-1, 1.5 kg phosphorous

ha-1day-1.

TABLE 3.3


Commercial systemsCommercial, integrated livestock-fish systemsare best developed in countries such as China,Taiwan and Thailand where vertically integrated

feed companies have exploited rapidly growingmarkets for meat and social, market and physicalconditions are optimal for using the largeamounts of waste through semi-intensive fish

Complex, multiple input systems were typified bystate and commune managed integrated farms inChina during the 1980s (Edwards, 1982). Thesecontrasted with traditional household systems inwhich fish yields were highly dependent on largequantities of green fodder consumed by grasscarp, in addition to small amounts of pig andhuman waste. The dike-pond systems of theZhujiang Delta were particularly complexinvolving multiple inputs, especially those relatingto production of silkworms (Ruddle and Zhong,1988). These systems, having reverted tohousehold responsibility under the rural reformsin the late 1970s, have also been most affected bythe drive to industrialization and urbanization inrecent years.

Prevailing prices in the 1980s favoured a grasscarp-dominated polyculture based on pasturegrass fertilized with pig manure, which was moreprofitable than the direct use of pig manure inponds stocked with filter feeding fish or feedingpellets. This reflected the lower price of filterfeeding fish even then, compared to grass carpand low cost of labour. Feeds at this time werealso relatively high priced, low quality and poorlysuited for the mainly planktivorous species raisedYang et al. (1994).

Aquaculture has had a variable developmentin different regions in China but its traditionalpractice is associated with provinces to the southand east; in other areas, particularly in the north,aquaculture is relatively recent. It is thereforeunsurprising that the level of intensification isuneven and Chen et al. (1995) analysis ofpractices by province gives a clear picture ofemerging trends that have since become moreapparent. Integration with livestock in the 1980swas of crucial importance to inland fish culture,with more than 80 percent of ponds receiving

manure of some type (Table 3.4). The systemswere characterized by the range of manures, andother inputs used. A trend towards specializationof livestock and fish production was evident asonly 22 percent of farms raising fish werephysically integrated with livestock at the time.The investment in feeds in the mid-1980s wasalready much more than fertilizers; all fertilizerstogether cost less than 8 percent of total nutrientcosts. Farmers were also spending more oninorganic fertilizers (56 percent of total fertilizercost) than manures (human 12 percent; pig/cattle28 percent and poultry 4 percent).

High yielding systems used most high-qualityfeeds and grass and snails, and they also relativelymore highly stocked with ‘fed’ fish, grass andblack carps, and omnivorous fish. In lower inputsystems (and poorer provinces), filter feeding fishdominated and fertilizer use (Figure 9) wasrelatively more important. However, even in ‘low’yielding systems, feed costs were 80 percent ormore and fertilizer only 20 percent. Certain otherdifferences were identified between provinces. InHunan, a ‘medium’ level fish yielding but livestock-dense province, a majority of ponds had livestockphysically integrated (73 percent), presumably asopportunity costs of the waste were low.Generally medium-yield fish farmers had the mostlivestock and were best diversified with respect toother sources of income. High yielding fish farmshad intensified stock management, spent more onfeed, fuel and equipment and specialized more invaluable fish species. They tended to raise fewerlivestock and derive less of their income from off-farm labour. Less than 3 percent of fishpondswere physically integrated with livestocksuggesting greater specialization and the reducedvalue of livestock waste at a certain level of inten-sification of fish culture.

Changing integrated systems in China

BOX 3.E


culture. Increasingly these are complex, multi-input systems in which the use of formulatedfeeds, aeration and improved strains are beingadopted to increase yields and returns. Theevolution of integrated fish culture in China givesa particularly interesting profile of howheterogeneous conditions stimulate differentpractices. Several studies based on data in the1980s do indicate some important trends in thecountry’s transformation (Box 3.E).

In locations where market and physicalconditions are suitable for both livestock andsemi-intensive fish production and theconcentration of livestock production lowers theopportunity cost of the wastes such asChacheongsao and Nakon Pathom provincesnear Bangkok in Thailand, direct physicalintegration of livestock and fish productiondevelop as in livestock dense provinces of China.Fluctuating livestock prices are common under

such conditions and Edwards (1985) showed thatfish production makes a significant contributionin covering losses when livestock prices are low.

The trends towards simplification ofintegrated systems with single species oflivestock raised at high density, and the use ofsupplementary feed and aeration has developedover the last two decades in China. There hasalso been substitution of livestock-fishintegration with more feed-based, fishproduction and diversification to higher valuespecies (Cremer et al., 1999). This appears to bemainly occurring in areas close to the major,richer markets where land is most limited, fishprices are high and high quality feeds areavailable. Nationally the situation still reflectsdependence, and increased growth, on fishraised in fertilized ponds and it is clear that Chinawill need to depend on integrated concepts tosustain inland aquaculture (Box 3.E).

Feed and fertilizer inputs in integrated systems for three areas with different levels of production in China

Composition by weight (t ha-1 year-1) Composition by cost (percent)Input Low Medium High Overall Low Medium High Overall

FeedsGrasses 20.91 35.24 59.65 44.53 22 18 18 18High quality 3.09 3.95 12.18 8.06 45 37 63 58Low quality 2.45 7.04 4.61 4.63 15 24 4 7Pellet feed 1.04 2.43 3.34 2.57 18 21 9 11Snails 0.00 0.03 16.55 8.71 0 0 7 5

Cost 1889 2112 6388 4303

FertilizersNightsoil 1.36 2.27 6.98 4.52 7 5 19 12Livestock manure 7.91 14.47 8.23 9.57 33 20 32 28Poultry manure 0.77 0.00 1.65 1.06 2 0 8 4Total manure 10.04 16.74 16.86 15.15 42 26 59 44Chemicals 0.84 1.93 0.53 0.92 58 74 41 56

Cost 359 520 298 364

TABLE 3.4

Source: Chen et al. (1995)


Inorganic fertilizationFarmers with limited numbers of livestock mayuse fertilization based on both livestock wastesand inorganic fertilizers. Inorganic fertilizers maybe a cheaper form of N and P than purchasedlivestock manure in many situations (Table 3.5),and highest yields may be achieved without, orwith relatively low loadings of manures. This maybe particularly the case for phytophagous fish

such as Nile tilapia. In highly productive pondsfertilized with inorganics (4 kg N.ha-1 d-1), theremay be no significant benefit of includingchicken manure in tilapia monocultures (Knud-Hansen et al., 1993). Green et al. (1994) recordedsimilarly high yields (>20 kg. ha-1 d-1) of Niletilapia using higher levels of chicken manure incombination with inorganic fertilizers.

The benefits of using high levels of inorganics

Percentage yield by fish species in three areas of productivity in China

FIGURE 9

0 2000 4000 6000 8000 10000

net yield (kg/ha/yr)

Grass carp

Filter feeders

Black carp

Omnivores

Source: Modified from Chen et al. (1995)

Economic comparison of different fertilizers with respect to available nitrogen (N), phosphorus (P), and carbon (C) (US$ = 25 Baht)

Available Available AvailableFertilizer Cost N P C

(Baht. 50 g-1) (Baht. kg-1) Baht. kg-1) (Baht. kg-1)

Chicken manure 20a 76b 194c 7d

Urea 240 10 - 24TSP 450 - 45 -NaHCO3 1000 - - 140

Source: Knud-Hansen et al. (1993)

a Wet weight; b assumes 40 percent dry weight of total N is available (Knud-Hansen et al., 1991);c assumes 10 percent dry weight of total P is available (Knud-Hansen et al., 1993)d assumes 50 percent dry weight of organic C oxidizes to dissolved inorganic carbon (DIC).

TABLE 3.5

HIGH

MEDIUM

LOW


may be constrained by their availability oropportunity cost. Other species may benefit morefrom use of manures, especially when high levelsof inorganic fertilization may be less appropriatesuch as for carp polycultures which include adetritivore. Supplementation of organic wastes inlow-input, chemically fertilized ponds increasedthe growth rate of mrigal, the detritivorous Indianmajor carp compared to controls (AASP, 1996).

Supplementary feedSupplementing limited livestock manure withdirect feeding of fish is an alternative strategy.The impact of supplementary feed on yields offish in ponds fertilized with livestock waste isaffected by many factors. The level of natural feedto some extent affects the efficiency with whichfish utilize supplementary feed. More natural feedallows use of more high-energy supplements to‘spare’ the protein requirements and support thegrowth of more fish (Chapter 5) The optimal levelsfor supplementary feeding are complicated bythe variable levels of waste feed that are mixedwith the manure which may be considerable.Purchasing supplementary feed for fish inlivestock-fish systems may not be cost effectivehowever, especially if feeding rates are high.

A reduction in feeding costs of more intensivesystems by fertilizing ponds with livestockmanure is another strategy that has attracted theattention of farmers and researchers alike. Asfeed cost typically comprises about 80 percent ofoperating costs of intensive aquaculture systems(Shang, 1981), any improvement in foodconversion efficiency is desirable. Clearly, the fishspecies raised need to be suitable for culture inwaste-fed, plankton-rich systems. Green et al.(1994) found that the tambaqui (Colossomamacropomum), in contrast to the Nile tilapia,grew poorly in fertilized systems withoutsupplementary feed. Increased levels of inputshave consequences for overall loading rates,water quality and fish yields (Chapter 5).

Microphagous Nile tilapia fed pelleted feed induck manured, mechanically aerated ponds inTaiwan yielded up to 18 tonnes ha-1 however(Liao and Chen, 1983) in systems that producedmost of the low cost tilapia exported to the USA.Hepher and Pruginin’s (1981) description of

commercial polycultures in Israel indicates thatfertilization with livestock waste and inorganicswas an essential component of high-yieldingsemi-intensive systems in that country. Feedingonly in the later stages of the culture period,when the nutritional needs of the fish exceed thelevel supported by natural feed alone may alsoreduce feed costs. Green et al. (1994) found thatat densities of 1 fish m-2, tilapia could be raisedon poultry waste alone for the first 90 days of a137 day production cycle without any differencesin final yield.

Integration with agro-industry3.3.1 GENERAL CONSIDERATIONS

Global market integration and commercializationgreatly increase the volume of animal waste (de

3.3

� Are inorganic fertilizers available and willtheir opportunity cost affect their use bythe farmers?

� Is the farmer raising mainly plankton-feed-ing fish, or species that feed in other nicheswithin the pond?

� How expensive are inorganic and organicfertilizers when costs per unit of availablenutrient are considered?

� What is the quality of wastes with whichthe feeds are being supplemented? Many‘wastes’ contain spilled feed.

What is the economically optimum level ofsupplementary feeding for the type ofwaste-fed aquaculture being used?

� Are supplementary feeds only profitable fornursing and fattening fish?

Summary of factors affecting useof inorganic fertilizer and feedswith livestock wastes

BOX 3.F


Haan et al., 1997). As incomes increase, a greaterproportion of animals and animal products areprocessed. Large quantities of homogenouswastes produced during production andprocessing of feedlot livestock make for economicuse of such by-products for fish feeds under avariety of conditions. Re-feeding manure andslaughterhouse waste back to livestock and fishhas been common in recent history (Chapman,1994). Early accounts of trout production indicatea dependence on old horses as fresh meat(Schaeperclaus, 1933) or as a substrate formaggots used as feeds (Rumsey, 1994). However,the use of meatmeals has come under increasedscrutiny recently after ineffective processing ofslaughter wastes led to outbreaks of bovinespongiform encephalitis (BSE) in cattle. Fish andshrimp meals are widely used as ingredients inboth animal and fish feeds. Both livestockproduction wastes i.e. manure andslaughterhouse wastes (blood, bones and viscera)

may be processed into conventional feedingredients used by feed mills (Figure 10),although only the latter is widespread.

The most important environmental impacts ofprocessing livestock result from the discharge ofwaste-water (de Haan et al., 1997). This area isleast developed with respect to integration withfish culture. A major problem in developingcountries is the tendency for processing plants tobe located in peri-urban areas whereinfrastructure and markets are best developedbut land and water are limiting.

Other major differences between modern andtraditional agro-industry are the facilities andscale of operation. There are large differences inthe type and quantities of by-products producedthat depend on the type of livestock andprocessing waste (Box 3.G).

Regulation of the size and distribution ofprocessing operations can encourage therecycling of processing wastes through

Comparison of possible strategies for using livestock production and processingwastes in aquaculture

FIGURE 10

LivestockProduction

Processing Maggots

Clarias Catfish Tilapia

SlaughterhouseWastesLivestock

Processing

Livestock

Manure


Processing


aquaculture. In Thailand, as road and otherinfrastructure have improved, chickenprocessing plants are moving away from flood-prone rice growing areas in provinces nearBangkok to the centres of broiler productionwithin maize growing, upland areas. Hybridcatfish farms which utilize much of their wastes,are similarly relocating to these areas(Ingthamjitr, 1997).

A major constraint to the use of most tannerywaste is the use of chromium in the tanningprocess. Chromium is particularly toxic to fishand other aquatic organisms. It is a majorproblem in the Calcutta wastewater-fed fisheries,causing seasonal mortalities and undocumentedrisks to humans from consumption of such fish.

Adding value to livestock wastes throughsimple on-farm processing has now developedwhere conditions are suitable: typically in thevicinity of larger towns and cities; and usuallyby entrepreneurs well connected with urbanmarkets. In one study, livestock processingwastes in Pathum Thani, Thailand were morecommonly used by farmers with diversified

farming systems (livestock, fish, vegetables,orchard), than rice farmers adopting fishproduction (Edwards et al., 1983). Location ofaquaculture within peri-urban zones alsomakes the use of other agro-industrial by-products possible. These include waste

� The biological oxygen demand (BOD) ofwastewater from red meat slaughterhous-es may be over 25 kg BOD. tonne liveweight-1, of which 10 kg is from blood,compared to less than 10 kg BOD. tonnelive weight-1 for poultry.

� Tanneries typically produce around 100 kgBOD tonne raw hide-1

� Dairies produce less than 5 kg BOD tonneof milk processed-1

� Markets also affect the value of theprocessed livestock. For example, whereasoffal may be highly prized and preferen-tially consumed in some markets, in othersit is a disposable waste

Source: de Haan et al. (1997)

By-products from livestock andprocessing waste

BOX 3.G

Limited land and/or water availability maypreclude conventional integrated waste-fedaquaculture. The production of a live feed,such as the green blowfly larvae, Luciliasericata, on pig manure and its use as asubstitute for a pelleted feed for intensivelyraised African catfish (Clarias gariepinus) incages placed in ponds stocked with Nile tilapia(Oreochromis niloticus) was demonstrated.

Key outcomes were� Catfish production of 6 tonnes year-1 based

on the manure from a standing herd of1000 fattening pigs was demonstrated

� The static water pond in which the catfishcages were suspended ensured that envi-ronmental impact of both pig and catfishsystems was minimal

� Integration of tilapia with catfish improvednitrogen retention by over 30 percent

� Manure after maggot production stillretained more than half the original nitro-gen content but its reduced moisture con-tent increased its value as a horticulturalinput

� Catfish fed maggots alone over an eightweek culture period grew to market size(100g)

� Catfish fed maggots alone fed had slightlylower survival (75-80 percent) than pellet-fedfish(>84 percent), possibly due to their vora-cious feeding that led to physical damage

Source: Nuov (1993); Nuov et al. (1995)

Green blowfly larvae used toprocess pig manure to fish feed

BOX 3.H


human food from canteens and restaurantsand food processing wastes. In Thailand andsome other parts of Asia, noodle processingwaste, stale noodles and bread products, andsoybean, brewery and distillery wastes arecommonly used. Many of these products arealso used for feeding livestock, particularlypigs (Figure 11).

Live-feed organismsThe use of livestock manures as substrates forlive-feed organisms such as insect larvae orcrustaceans for feeding high-value fish also haspotential where land costs prohibit semi-intensive aquaculture. Live feeds can be used as

complete diets or to supplement pelleted feedsfor fish species such as hybrid Clarias catfishraised in intensive systems (Box 3.H). Such low-tech solutions not only produce fish but alsoincrease the value of the original waste,principally by reducing smell and moisture level.

Slaughter house wastesCommercial examples of poultry slaughter housewastes being used as feed after simpleprocessing for carnivorous fish such as Clariascatfish and snakehead exist in Asia (Box 3.I). Therapid deterioration of viscera and otherslaughterhouse wastes restricts their use to areasclose to the source. In Thailand such wastes are

TOP LEFT

Maggot production based on pig manure. Green blowfly(Lucilia sericata) larvae are raised in batches over 4-5 daysand fed to African catfish

TOP RIGHT

Maggots being produced in manure placed next to fishponds can be pushed into the water to feed the fish

LEFT

Feeding broiler chicken intestines to Pangasius catfish


FIGURE 11

Source: AIT (1983)

Percentage of farms in Central Thailand using various fertilizer and supplementary feedinputs for fish culture (a) waste food from human consumption and agro-industry (b) ani-mal by-products and animal feed (c) vegetable matter.

Purchased Domestic Soybean Bread chip Noodle Inferior gradefood waste waste food waste waste processing wastes mung bean

Trash fish Animal Trapped Industrial feed Concentrateprocessing waste insects chicken feed

40

35

30

25

20

15

10

5

0

40

35

30

25

20

15

10

5

0

Perc

enta

ge o

f fa

rms

Perc

enta

ge o

f fa

rms

Waste Duckweed Water Water Other Grassvegetables spinach hyacinth Acquatic weeds

40

35

30

25

20

15

10

5

0

Perc

enta

ge o

f fa

rms

(a)

(c)

(b)

no rice cultivation

rice cultivation


usually refrigerated on-farm and may be traded.The advantages of an export industry that bothstimulate employment producing value-addedproducts and produces food for sale locally areclear (Box 3.J).

Poultry slaughter house wastes are in greatdemand for feeding hybrid Clarias catfish (C.macrocephalus x C. gariepinus) in Thailand. Thepractice has evolved on the back of a boomingindustry and export of boneless chicken meat inwhich broilers are processed in-countryproducing large amounts of by-products.Heads, viscera and thighbones, that constituteabout 10 percent of the liveweight of the broilerare the main by-products fed fresh after simpleon-farm grinding and mixing with a binder.

Food conversion ratios of 4-5 (wet:wetbasis) are attained under farm conditions inwhich yields of the air-breathing hybrid catfishmay exceed 100 tonnes. ha-1. Competition topurchase slaughterhouse by-products hasresulted in segmentation of the recyclingbusiness with wholesalers contracting waste, tofurther remove meat scraps for humanconsumption before use of residual waste forcatfish feed.

Effluents from the fish culture systems areminor as water exchange is minimal andincreasingly is pumped into neighbouring pondsin which polycultures of herbivorous fish areraised in fertilized, semi-intensive systems.

Source: Little et al. (1994)

Chicken slaughter house wastefed to catfish

BOX 3.I

1st order benefits� Local maize and soybean production stimu-

lates broiler production

� Broiler production waste used to raise her-bivorous fish

� Local labour used for de-boning chicken

� Chicken slaughter wastes used to raise cat-fish

2nd order benefits� Expertise in feed manufacture stimulates

development of value-added feed ingredi-ents and knowledge

� Benefits to crop farmers (stable markets)

� Benefits for peri-urban skilled and unskilledemployment

� Low-cost chicken and fish products for salebenefit local consumers

� Reduction in polluting effluents

Feeding maize to catfish

BOX 3.J

After processing of broiler chickens in Thailand about10 percent of the liveweight is used for feedinghybrid Clarias catfish

CHAPTER 4 • ENVIRONMENTAL ASPECTS 47

Environmental Aspects

4

The interaction of livestock and fish, either as specialized or

integrated activities, and the environment can be considered in two ways (1) how the

environment impacts on opportunities for livestock and fish production and (2) how

livestock and fish production impact on the environment. Impacts can be positive or

negative in both directions (Figure 12); in this section we explain how integration

tends to enhance positive and minimize negative impacts.

Clearly both fish and livestock production arestrongly influenced by, and affect, their agro-ecology. Aquaculture, by nature of the aquaticenvironment, is often integral to, and difficult toseparate from, surrounding natural and humanhabitats such as rivers, lakes, reservoirs andcoastal areas. Aquaculture has closer proximityto ‘wild’ organisms than animal husbandry thatmay threaten (through disease transfer,parasitism or predation) or support (throughsupply of seed or feed) aquaculture (Edwards,1997). The key reliance on water leads to anenhanced vulnerability to pollutants andcontaminants moving with water in and out ofaquaculture systems because of the fluidmedium.

Impacts on the environment of livestockconsidered alone, aquaculture alone or both

together have both a local and globalsignificance. There are two major interrelatedproblems facing developing countries and theirrelationship with the wider world. Sustainingpoor peoples’ livelihoods directly, and indirectly,through enhanced agricultural productivity and,at the same time, ensuring that local and globalenvironments are safeguarded. How nutrientsare used, and recycled, in food production is ofmajor importance to meeting these challenges.Water, and how food production affects itsavailability for other uses, is of majorsignificance, not only to the sustainability of localcommunities but also to broader geopoliticalstability. Irrigation systems that promiseincreases in arable crop yields and cultured fishproduction, typically undermine importantriverine and flood-plain fisheries that may be


fundamental to the food security needs of thepoor. The integration of livestock and fishproduction may contribute to stabilising nutrientand water use, allowing increasing demands tobe satisfied.

More resource-intensive, livestock and fishfarming will have increasingly negative impactson the global environment. These include theeffects on global warming to which they directlyand indirectly contribute. Fossil fuel use that isthe major underlying cause of greenhouse gasproduction, supports much of the current foodgrain and concentrate production that underpinsthe culture of livestock and carnivorous fishspecies. The impact of increasing demand forconcentrate feed on arable systems and theworld’s natural stocks of fish to support growth inintensive livestock and fish production could bereduced if integrated farming became morewidespread.

Local development of productive integratedsystems can also contribute positively to the

maintenance of biodiversity. There are twoimportant aspects; reducing impacts on naturalresources and adding value to local strains andvarieties. Maintaining the genetic diversity ofboth wild and cultured animals and plants iscritical for longer-term sustainability of bothsmall-holder and large-scale commercial foodproduction.

NutrientsIntensive recycling of nutrients was critical tosupport dense rural populations, such astraditionally occurred in much of Eastern Asia(King, 1911). Urbanization and industrialization ofagriculture have led to de-linking of nutrientrecycling and production to produce food, or inthe words of Borgstrom (1973): ‘the breach in theflow of mineral nutrients’. The flow of nutrients

4.1

The two-way interaction between aquaculture and the environment involvesnumerous factors which range from positive to negative in their impact.

FIGURE 12

Source: Modified from FAO (1997a)

Positive

Separated Integrated

Negative

Positive

Impact of environment on livestock and/or fish

Separated Integrated

Impact of livestock and/or fishon environment

Negative

entering urban centres as food via processingand distribution systems has becomeunidirectional - a development that has beenaccelerated by sewerage systems that channelhuman wastes away from densely populated citycentres (Vallentyne, 1974). Alternative fertilizers,firstly guano and later industrially manufacturedfertilizers, began to free farmers from dependenceon local nutrient recycling.

A serious geographical imbalance in nutrientdistribution now exists; large amounts ofnutrients are imported into industrial regions thatthen spend large amounts of money to avoideutrophication. In contrast developing areas,which sometimes are the original source of thenutrients, are becoming nutrient-depleted.Cropping cassava on fragile tropical soils forexport as low-cost livestock feed ingredients fordeveloped countries is both unsustainable on alocal scale and, through deforestation anderosion, has much broader adverseenvironmental impacts. Intense exploitation offish stocks to produce fish meal has majorimplications for the integrity of marineecosystems. The international trade incommodities has driven many of these practices,but many poorer peoples’ livelihoods are nowdependent on them.

Aquatic systems have been used for nutrientdisposal, both intentional and accidental sincethe beginnings of human settlement. Removal ofthe mainly organic wastes of people settledaround waterways and waterbodies wasconvenient and, initially, left few traces. As thenutrient load increases however, water qualitydeteriorates with a number of obvious effects.The silting up and nutrient enrichment ofcommunity reservoirs and dams causes as manyproblems to communities around them as thedisposal of sewage in industrialized countries.Shallow community water bodies commonlybecome choked with unmanaged macrophytevegetation or waterways become plankton-richand, if organic loads are unchecked, hyper-eutrophic and eventually anaerobic. Both types ofplants can be the basis for nutrient recovery ifused within managed systems and examplesexist of both traditional and modern systems.

Aquatic macrophytes can remove nutrients andhave been important components in integratedfarms in China and Northern Viet Nam to feedboth pigs and herbivorous fish. Plankton-basedaquaculture is the basis of semi-intensiveproduction of filter feeding fish.

4.1.1 NUTRIENT RECYCLING IN AGROECOSYSTEMS Agroecosystems differ from natural, unmanagedecosystems in their larger and more rapidturnover of nutrients. Such systems producingfood or fibre are therefore more open for nutrienttransport across boundaries (Frissel, 1977; Tivy,1987). Moreover, the level of nutrient inputs usedcan define the intensity of farming. Modeling ofnutrient cycling is well established forconventional agriculture (Figure 13) but analysisof agroecosystems involving crops, livestock andfish is recent. Understanding how a pond stockedwith fish affects fluxes of nutrients through thefarm can be critical to developing more efficientand less polluting agriculture, animal husbandryand aquaculture.

Extensive agriculture, such as unimprovedpastoral systems, relies on the natural or littlemodified soil nutrient reservoir, and has lowyields of biomass and nutrients (<20 kg N ha-1).In contrast, specialized intensive agriculturerequires large nutrient imports but shows highproductivity. Nitrogen outputs of intensive grassproduction can exceed 400 kg N ha-1 (Frissel,1977). Feedlot livestock can greatly exceed thesevalues because high-density livestock are fedconcentrates.

Mixed farming is generally intermediatebetween these two extremes, receiving low tomoderate inputs from outside. The closerelationship between wastes from livestock usedfor fertilization of crops, and use of N-fixing plantsboth reduce the need for N imports, and improvenutrient efficiency. Farming systems in whichlong-lived organisms such as perennial crops andlarge livestock are important components aremore like self-sustaining natural cycles withincreased system biomass and reduced primaryproductivity/biomass ratios (Dalsgaard et al.,1995).



Nutrient cycles for an agroecosystem involving crops, fish and livestock. The crops, livestock and soil pathways, for which the major linkages are brown arrows, are repro-duced unmodified from Tivy (1987). The fishpond, its major linkages with crops and live-stock (dark green arrows), other inputs and outputs have been added here. Nutrient recy-cling within and between the fishpond water and mud are omitted for clarity. In some tra-ditional Asian systems, human (household) excreta is an important additional input tocrops and fishponds and kitchen waste the livestock and fishponds.

FIGURE 13

From atmosphere

From atmosphere

Crop remains+ seed

Uptake from soil

Fish/fry fingerlings

Supplemental feed/fertilizer

Fish + other aquatic

produce

Excreta (manure + urine)and waste/spilled feed

Livestock

Seeds

Crops

Volatilization

DenitrificationDust

Run-off

Leaching

Fodder crops

Forage

Volatilizationmanure

Volatilization

Cut vegetation

Manure

From atmosphere

N-fixation

Fertilization

Irrigation

FeedLitter

ManureManure

Manure

Source: Edwards (1993)

Livestock

Mud

Immobilization Mineralization

Organic

Inorganic

Weathering Fixation

Available soil nutrients

Crop remains,by products (no seed)

Fertile water Water

Water Fishpond

Trash fish /aquatic biotic


However, even a simplistic analysis ofnutrient fluxes can indicate that mixed orintegrated farming systems can be far from aclosed ecological cycle. Imports of pig and humanfood into the seemingly tightly managedagroecosystems in Southern China were requiredto support the large nutrient exports ofcommodities such as silk, fish and sugar(Edwards, 1993) and a similar situation exists inNorthern Viet Nam (Box 4.A).

A key factor in estimating overall systemefficiency is not only the harvestable yield from agiven level of input, but the practicality and yieldfrom organisms raised on recycled nutrients inthe waste. The relative ‘leakiness’ of nutrientsfrom agroecosystems, as run-off and leaching andpercolation into subsoil, and ultimately aquifers isalso relevant. Decomposition of livestockmanures spread on field crops and leaching ofnutrients is a major environmental problem, evenin developing countries where nutrients are

In an analysis of nutrient flows in and through avillage in the Red River Delta in NorthernViet Nam, the majority of nutrients left as ricegrain and food products processed from rice i.e.noodles, wine and pigs. A substantial surplus ofnutrients was also found to be leaving the fieldsin drainage water, polluting the water sourceinto which it flows. Most crops and cropresidues were consumed in the village, fed tolivestock, used for making manure/compost orburned for fuel. Chemical fertilizers were themajor source of nutrient inflow to the villagesystem (Figure 14).

Source: Le and Rambo (1993)

Nutrient flows among village subsystems and between village and outside systems inNguyen Xa village, Viet Nam.

BOX 4.A

Nutrient flows among village subsystems and between village and outside systems.

FIGURE 14

Atmospheric N

Sediments irrigation

Chemical fertilizers

Rice and rice

products

Potato

Pig

Fish

Source: Le and Rambo (1993)

EX

TE

RN

AL

SY

ST

EM

S

Rice

Straw, grasses for fodder

Straw husk

Manure

Mea

t

CompostNight soilRice, husk, straw

MeatHh, waste

Manure

Man

ure

Man

ure

Nig

ht s

oil

AshMan

ure

Stra

w,

husk

, gr

asse

s

Cro

p r

esid

ues

Kitchenwaste

Meat

Meat

feed (aquatic vegetables

and weeds)Manure

Mud for fertilizer

swee

t p

otat

o,

pot

ato,

cor

n,

soyb

ean’

pea

nut

Ric

e br

an

Manure

Fodd

er

Wet rice field

Compost pit

Buffalo andcattle

Roadside andpaddy bunds

PoultryFarm

household

FishpondHomegarden

Pig pen

Pig

Night soil collection place

limiting (see Box 4.B). Intensive specializedlivestock production tends to lead to a greaterwaste of nutrients. In the Netherlands, 52 percentof pig manure, 60 percent of manure of fatteningcalves and 80 percent of chicken manure iswasted (Harrison, 1992).

4.1.2 NUTRIENT EFFICIENCY INLIVESTOCK

Relative efficiencies of livestockThe role of livestock in supporting humanpopulations, and their relative efficiency in termsof using land and food resources, are highlyspecific to the human and agro-ecology of theregion. Whereas monogastrics (pigs and poultry)may compete for cereals, pulses andconcentrates suitable for direct humanconsumption, ruminants may utilize plantproduction unsuitable for direct human food.Livestock can have important roles in improvingtotal efficiency of conversion through use of by-products unsuitable for, or wastes from, directhuman consumption. Spedding (1984) observedhow monogastric and ruminant feeddevelopment could be synergistic. Extraction ofenergy/protein-dense food from herbage crops forpigs and poultry, leaving residues with value forruminants, is one option. A good example of thisis the use of sugar cane juice in pig feeds inViet Nam (Preston, 1990). Another strategy is thebiological processing of fibrous wastes in whichearthworms or dipterous larvae are used toconcentrate high-quality, microbial protein fromdecomposing animal and vegetable waste.

Any comparison of livestock in terms ofnutrient efficiency is problematic. Proteinconversion values, or protein to energy ratioshave been used but any meaningful comparisonis difficult because different animals can usedifferent quality feeds. Thus, although poultryyield most protein per unit of gross energy fedcompared to a range of other animals, the feedsused contain a higher proportion of metabolisableenergy (ME), usually in the form of moreexpensive feeds. Efficiency expressed as proteinconversion or protein per unit of energyconsumed (g protein/MJ of ME) of single animalsindicates that eggs, milk, milk plus beef, poultry

and pig production are high and breedinganimals low. But any animal production requiresbreeding animals and thus consideration ofnutrient efficiency has to be made on the basis ofpopulations rather than single animals. A highreproductive rate and low turnover of breedinganimals improves overall efficiency. Highlyproductive pigs and poultry have low overheadfeed costs for breeding animals compared tolarger animals. Selection for earlier age at firstbreeding, reduced length of and improvedregularity of a breeding cycle, greater fecundityand improved early survival of the young, alltheoretically improve reproductive efficiency. Inpractice they may be counteractive or incur suchhigh support costs as to be impractical. It is alsoknown that separation of males and females anduse of different diets and management canenhance feed utilization, but may not bepractical.

Approaches to improve efficiencyDifferent approaches are known to improveoverall efficiency of nutrient use in ruminants andmonogastrics. Replacement of traditional sourcesof protein with non-protein N is one approachuseful for ruminants. Use of micro-nutrient blocksfor animals consuming poor-quality diets, anduse of by-pass protein can all increase theefficiency of protein use. Development of dietswith improved amino acid balance and optimalrelationships between micro-nutrients hasimproved the nutrient efficiency of monogastrics.

Modern livestock systems can producerelatively less waste but it is often more nutrient-rich than from traditional systems. Certainpractices influence the amounts of N and P (Box 4.B).

4.1.3 NUTRIENT EFFICIENCY INAQUACULTURE

A comparison of intensive and semi-intensiveaquaculture reveals that conversion efficienciesare greater for fish fed formulated diets (21-53percent for N, 11-28 percent P) than fish raised inponds receiving livestock manure or inorganicfertilizer (5-25 percent and 5-11 percentrespectively) (Edwards, 1993). However, these



differences reflect a fertilized system in whichphytoplankton is produced; and are far from a 90percent decline in efficiency expected from anextra step in the food chain. The values reflect thehigh degree of nutrient recycling that occurs infood webs in fertilized ponds and, particularly inpolycultures, how efficiently they are exploited.

Developments in intensive salmonidproduction are towards ‘low pollution’ diets inwhich highly refined processing of foodingredients produces more highly digestible, lowP diets. These have resulted in declines inmeasured P effluents, despite rising production.However this has been achieved largely throughuse of greater amounts of fishmeal, withassociated environmental impacts. Additionally,the level of soluble, excreted nutrients. (kg fishproduced-1) have probably increased with theuse of such diets.

4.1.4 NUTRIENT RELATIONSHIPS INLIVESTOCK-FISH SYSTEMS

Integration of livestock and fish production canimprove the overall efficiency of nutrient use in thesystem and reduce the level of effluents. Relativeinefficiencies in nutrient use by livestock can becompensated for by recycling in fish production.Efficiency of nutrient recovery declines as inputlevels increase, a clear case of diminishingmarginal returns (Table 4.1). There are alsodifferences in efficiency of nutrient transferbetween wastes collected from different livestocksystems. Both fish yield and N recovery wereconsiderably poorer for ruminants fed poor-qualitydiets than feedlot ducks fed complete feeds. Suchinformation is useful for estimation of opportunitycosts of livestock-fish systems (Chapter 7).

Wastes are often composed of fractions ofdifferent value to fish culture. The mixing of feedwith manure for example can improve its valueand nutrient recovery of the overall waste. Adlibitum feeding of ducks resulted in an estimated10 percent of the feed being wasted and directlyavailable to the fish in the case above. In ducks,species, sex and type of feed were all found tosignificantly affect feeding efficiency and theamount of waste feed ‘lost’ to direct consumptionby fish in integrated systems (Naing, 1990).

� Supply nutrients to the required level. Thiscan be accomplished by better knowledgeof nutrient availability (N, P) in the feed, abetter knowledge of the animals require-ment and a better agreement of supply andrequirement.

� Enhance digestibility of P and protein. Useof microbial phytase to improve digestibili-ty of P reduces needs for supplementation;enzyme treatment of non-starch polysac-charides; reduce anti-nutritional factorsthrough treatment of ingredients and pro-cessing of complete diets.

� Change feedstuff composition. For exam-ple selection of highly digestible sources ofP (mono-calcium phosphate rather than di-calcium); use of amino acid supplementa-tion and reduction in protein levels.

� Improve feed efficiency.

Other environmental effects:

� Levels of potassium supply exceeddemand by a factor of 3-5 and levels infresh water can exceed accepted levels bya factor of 2-4.

� High moisture level of livestock wasteincreases transport costs for disposal.

� Although feed additives may reduce excre-tion of N and P as a result of better feedconversion, copper and zinc growth pro-motants can accumulate in soils.

� Free-ranging pigs requiring more fibre inthe diet have lower feed conversion andmore waste per unit of meat produced.

� Specific pathogen-free herds can improvefeed conversion by 10-15 percent.

Source: Modified from Jongbloed and Lenis (1995)

Approaches to reducing livestock waste and environmental pollution

BOX 4.B


Significance of livestock andfish production in the globalenvironmentLivestock and fish production impact on thewider environment in a variety of ways. Theresources used to feed, maintain, process anddistribute livestock and fish products areconsiderable. However, intensified production ofboth livestock and fish must occur if naturalhabitats are to be preserved (de Haan et al., 1997).

Intensification of livestock based on knowntechnologies adapted to local situations couldreduce impacts on the remaining naturalenvironment (Murgueitio, 1990). While intensivelivestock production is a major source ofpollution, degradation of range lands and soilerosion in developing countries is associatedwith increased numbers of ruminants that areoften extensively managed and of lowproductivity (Steinfeld et al., 1997). Extensivelymanaged ruminants have been identified as amajor factor in both tropical deforestation andincrease in greenhouse gases. These claims areparticularly important given the growth inlivestock production, which at 4.5 percent year-1,

is higher than for agricultural production as a whole.

4.2.1 GLOBAL WARMING

Agriculture has been implicated as a major causeof global warming that is leading to adversechanges in the world’s environment. Theseinclude rising sea-levels that are likely toparticularly affect densely populated flood-plainsin Asia, communities that are also mostdependent on cultured freshwater fish. Thisdependence is set to increase substantially, andthe poorest are most at risk (Harrison, 1992).

Carbon dioxide, nitrous oxide and methaneare the main ‘greenhouse gases’ linked directlyand indirectly to livestock production. Permanentcarbon release is mainly related to use of fossilfuels and deforestation, for which intensiveanimal husbandry and extensive ruminantproduction, respectively, are important. Nitrousoxides are associated with production and use ofN-fertilized pasture and arable crop-basedfeeding.

Livestock and manure managementcontribute about 16 percent of total annualproduction of methane (de Haan et al., 1997) andunproductive ruminants contribute especially toemissions (Leng, 1991). A larger fraction of feed is

4.2

Efficiency of N recovery in livestock-waste fertilized earthen ponds (200 m-2)stocked with Nile tilapia.

Livestock NitrogenNumber of adult Number of Extrapolated g to produce Conversion

buffalos. egg-laying ducks. fish yield 1 kg fish efficiency (percent)ha-1 pond ha-1 pond (tonnes ha-1 yr-1)

500 4.8 119 221000 8.0 143 181500 10.1 169 15

50 1.9 226 11100 2.6 331 8150 3.1 417 6

Source: AIT (1986)

TABLE 4.1

used for maintenance in low productivityanimals, resulting in a higher level of methaneproduced per unit of product. Also, lower qualityfeeds with poorer digestibility have higheremissions per unit of feed intake. Intensifyinglivestock production could therefore haveimpacts on both global warming and livestockproductivity. More than 80 percent of methanefrom livestock arises from digestive fermentationand the balance is linked to manuremanagement. Manure handled dry produces littlemethane, but feedlots, which produce large

amounts of liquid manure, are the maincontributors. Pigs and poultry cannot digestfibrous feeds and have relatively lowfermentation emissions; the rapid increase in thenumbers of these monogastrics compared tograzing animals on a world-wide basis is onereason for the stagnant methane emissions fromlivestock, despite growing numbers (de Haan etal., 1997). Improved productivity is also believedto contribute to stability of methane emissionsrelated to digestion.

The recycling of methane after controlledcollection and digestion is attractive, particularlyfor large pig and dairy operations with highenergy requirements but has been less attractivefor small-holders. Lower cost systems based onlow-cost polyethylene tubing have also beenpromoted in the Mekong Delta, Viet Nam(Herrera, 1996). Farmers raising fish, however,prefer to use fresh pig manure directly and biogasslurry is rarely used to fertilize ponds (Bui, 1996).The disposal, with or without intermediatefermentation in a biodigester, of feedlot livestockwastes in aerobic fishponds would reducemethane and CO2 emissions considerably.

Expansion of fertilized aquatic systemsstocked with grazing fish has greater capacity forsequestering carbon dioxide than even well-managed terrestrial pasture, as aquaticproductivity may be most limited by carbon inotherwise fertile systems. Flooded rice fields ofAsia have been identified as another majorsource of methane. The stocking of rice fieldswith fish that graze the soil-water boundary inricefields ensures that it remains aerobic, withmethane production correspondingly reduced.

4.2.2 WATER USE

Water is a renewable resource but its availability,if considered as the amount per person per year,is limited. Increasing water scarcity isundermining food security and becoming thecause of local and international conflicts(Falkenmark, 1999). Whereas water consumptionof livestock is related mainly to the amountsrequired to produce their feed or fodder (Pimentelet al., 1997), the water used for holding fishduring production needs to be considered in


� Aquatic systems have often been used fordisposal of waste nutrients, leading towater quality deterioration

� Agricultural systems are characterized bygreater nutrient fluxes than natural systems

� Sediments in aquatic systems can act assinks for nutrients, aiding in their conserva-tion and use

� Leakiness occurs in all agro-ecosystems,especially the intensive, but integrated sys-tems tend to recycle a greater proportion ofnutrients in the system

� Assessment of the use of nutrients by live-stock needs to consider population effi-ciency and the value of the feed converted

� The feed industry approach to improvedefficiency is based on refining performancethrough formulations that meet the animalsneeds more exactly

� Conventional feed efficiency of intensiveaquaculture is high and progress has beenmade towards less polluting diets

� Semi-intensive aquaculture has high sys-tem efficiency

� Integration of livestock and fish can com-pensate for poor feeding efficiency in thelivestock alone

Summary of nutrients and theenvironment

BOX 4.C


aquaculture (Beveridge and Phillips, 1993).Levels of seepage, evaporation and recycling ofwater in fish culture systems are thereforeimportant criteria, as is the value of water after itsuse for fish production.

Water use efficiencies of livestock aredependent on both the type of feed given and theefficiencies of conversion. Intensively fattenedbeef dependent on irrigated crops is thereforewater hungry. In contrast, poultry as efficientconverters of diets mainly consisting of rain-fedcereals (sorghum, maize and wheat), can beproduced using much less water.

The integration of livestock and fishproduction can reduce the amount of water usedper unit of animal protein, compared to separate,stand alone production of poultry and fish inponds (Table 4.2). This is basically because theamount of water required to produce feed for fishis eliminated. In more intensive systems,however, water can be used more efficiently if thefish are fed and raised at higher densities, andwater is filtered and recycled.

A direct comparison of the efficiency of wateruse in different livestock and aquaculturesystems is not realistic in other ways. Theconstruction and siting of fishponds inwatersheds to collect and store water thatotherwise would be unavailable contributes toincreasing the amount of available water for thewhole farming system i.e. fish, livestock and cropcomponents. The capital costs for any singlecomponent might be too high whereas theintegrated use of the water ‘spares’ this initialcost, and reduces risk (Chapter 9). Moreoverintegrating livestock waste with semi-intensivefish production may increase the ‘value’ of thewater since its nutrient level, and hence value forirrigation, will be increased when used locally inagriculture (Little and Muir, 1987; Pullin andPrein, 1994).

The potential and constraints to theintegration of livestock and fish are reviewed bysystem in Table 4.3. Open ponds within diversefarming systems offer most potential forsignificant interaction. Water shortages havebeen an important motivation for closer spatialintegration between livestock, fish and cropproduction in parts of Asia (Box 4.D).

Intensive fish production, especially in cagesand raceways, tends to be highly consumptive ofwater (Table 4.2), degrading the value of largeamounts of water required by other consumers.Regulators in the industrialized world viewintensive aquaculture as a polluter ofmultipurpose water resources and tend to limitits size and distribution. Eutrophic waterenriched by wastes from intensive aquaculture orlivestock production requires extra treatmentcosts prior to distribution and use.

4.2.3 BIODIVERSITY

The case has been made for intensification oflivestock production to safeguard remainingareas of wildlife habitat and, indirectly,biodiversity (de Haan et al., 1997). The expansionof fish culture, closely integrated with thisintensified livestock production may also reapspecific benefits in terms of protection of aquatichabitats. Exploitation of wild fish stocks hascontributed towards collapse or impoverishmentof native fauna but this is often based onindustrial fishing to produce fish meal for feeding

� In Northeast Thailand, ricefield-pond sys-tems became foci for intensified integratedfarming but water availability for dry-sea-son vegetables for home consumption wasthe primary motivation. Less poultry dis-ease in flocks raised in the system andperennial water for raising fish were sec-ondary motivations (Surintaraseree andLittle, 1998).

� On-farm reservoirs in Central Luzon,Philippines, have allowed farmers to bothplant a dry season rice crop and earn anadditional 20 percent net income from fish,but in drier areas competition betweenwater use for rice and fish in irrigation sys-tems occurred (Fujisaka, 1993).

A need for water encourages integrated fish culture

BOX 4.D


intensively raised livestock and fish. Low-costfarmed fish can reduce these pressures, and theaccompanying environmental degradation, byproviding the market with alternative supplies,perhaps to a point where natural stocks canrecover although this is probably unrealistic due

to growing population pressure and differentplayers catching and culturing fish.

The drainage or conversion of wetlands foraquaculture is a common strategy that riskslosses to both biodiversity and the livelihoods ofthe poor (Chapter 7). Culture systems that

TABLE 4.2

Potentials and constraints to integration of livestock with fish by system

System Potential for livestock waste Fish densities/level Predisposing conditions Environmental providing significant of intensification impactsnutrients to fish production

Open ponds High, proven concept Low-medium Waste recycling tradition; Minimal, possibilitylow fish: feed cost ratio; of seepage to well developed livestock ground waterindustry

Ponds/tanks Low Medium-high Water shortage; high Minimal, design and with fish:feed cost ratio management densityrecirculation dependentCages Some Medium-very high High cost of land/water Potentially very high

for pond aquaculture; availability of reservoirs/lakes; moderate to high fish:feed cost ratio

Raceways None High-very high Low cost; high quality High, little possibility water source; high fish: of nutrient removal feed cost ratio because low

concentration/highvolume

TABLE 4.3

Water consumption of fish production integrated with livestock or as astand-alone enterprise

System Water consumption (m3 t-1) Source

Feed Environmenta

related related Total

Beef b 100 000 Pimentel et al. (1997); feedlot fattenedBroiler chicken b 3 500 Pimentel et al. (1997)Tilapia polycultures integrated with broiler chicken 6 060 6 060 Hopkins and Cruz (1982); PhilippinesTilapia monoculture: � Intensive earthen ponds <3 500 8 000 <11 500 Mires and Anjouni (1997); Israel� ‘Dekel’ system <3 500 460 <3 960 Mires and Anjouni (1997); Israel� Tanks <3 500 50 000-60 000 >50 000 Beveridge and Phillips (1993); Kenyaaseepage, evaporation; blivestock alone

depend on modification, rather than wholesalechange of natural habitats and use indigenousspecies need greater attention in this respect.

The use of indigenous fish in culture mayresult in conservation of endangered species.There has been relatively little development ofpolycultures based on indigenous fish butexperience in Java, where combinations ofseveral indigenous carps and gouramis aretraditionally cultured, suggests this is apromising strategy. Moreover, most fish eatingcultures that have relied on natural stocks arefamiliar with consuming fish of a variety ofspecies and size. One constraint is that manyhighly valued indigenous species are carnivorousand not good primary culture candidates. Theymay be useful, however, as components of semi-intensive systems that add value to polyculturesmainly comprised of low value herbivorous fish.Stocking a variety of indigenous, carnivorous fishalong with snakeskin gourami (Trichogasterpectoralis) is now a well-developed system inThailand. The need for more diversity wasmarket-driven and favoured use of indigenousand exotic species raised together to suit localneeds (Yoonpundh, 1977). Production wasenhanced using livestock manures and thesystem has emerged as an alternative strategy tohigh-risk intensification based on monoculture. Italso allows resource-poor farmers to raise specieswith which they are familiar, and which are ofhigh value.

Combinations of wildlife and livestock arenow recognized for their value in increasingbiodiversity and incomes for the peopledependent on them such as pastoralists andranchers (Steinfeld et al., 1997). The survival ofwild aquatic species and their habitats, may alsobe more assured if they can be utilized withinextensive and semi-intensive culture systems.

Integrated fish culture protects biodiversity inmore indirect ways. Increased demand for feedconcentrates creates significant pressures on theenvironment and aquatic habitats in particularthrough high rates of water extraction and thedeterioration in quality that often occurs. Largequantities of both surface and ground water areused to irrigate cereal and oil crops that comprise

most concentrates, and contamination of waterrun-off and drainage with agrochemicalstypically occurs. When concentrates are used insemi-intensive systems, more fish can beproduced per unit feed than intensive systems inwhich natural food is unimportant.

4.2.4 USE OF FISHERIES TO SUPPORT LIVESTOCK AND FISH PRODUCTION

Integration of livestock and fish is highly efficientif the fish species raised are herbivorous oromnivorous. The production of carnivorous fishhas implications for equitable use of resources(see Chapter 7) since the small trash fish requiredto either feed them directly (as in certain catfishand snakehead systems in Southeast Asia) orindirectly for fishmeal production can be eatendirectly by the poor.

Intensive aquaculture of carnivorous speciesuses a rapidly increasing proportion of the limitedglobal supply of fishmeal as fish inputs are two tofour times the volume of fish outputs in theproduction of farmed salmon and shrimp (Nayloret al., 1998). Although the amount of fishmealused in livestock diets has declined recently,particularly for grower and finishing feeds ofmonogastrics, livestock remains the major user atabout 75 percent of global production.

Cultured fish may be used increasingly tosupply fresh fish and fishmeal needs. Productioncosts for waste-fed herbivorous fish are nowsimilar to the price paid by manufacturers ofvalued added products such as pet foods forquality trash fish. Market pressures may alsostimulate the emergence and acceptability ofwaste-fed fish for these purposes as consumersare becoming increasingly aware ofenvironmental issues.

The use of small quantities of cultured fish tobalance carbohydrate-rich on-farm diets forlivestock has been suggested (Chapter 9).

4.2.5 IMPACTS OF LIVESTOCK SYSTEMS ON FISH PRODUCTION

Water pollution caused by residues andpurposeful disposal of chemicals used in



livestock production is typically highly harmful tofish and other aquatic organisms. Poor fishgrowth and survival in a system based on goatwastes from animals dosed prophylatically withanti-helminths has been reported in experimentalsystems (Mohsinuzzaman, 1992). Water pollutionfrom agrochemicals to control livestock diseasevectors such as ticks and tetse fly can negativelyaffect fish if inappropriate drainage or dischargeis used.

In temperate climates, attention has beendrawn to the negative impacts of grazing animalson riparian systems, around which they are oftenconcentrated, through their consumption ofvegetation cover and resulting run-off. Increasednitrate and phosphate levels affect plantcommunities, silt deposition and flow dynamicsof surface waters. Aquaculture integrated withinthe farming system, especially of less tolerantspecies, can act as a bio-indicator ofenvironmental health.

� Both intensification and extensification oflivestock production threaten the global envi-ronment; intensive aquaculture is also oftenenvironmentally unfriendly

� Increases in deforestation and greenhousegases, and a deterioration in water quality, aredirect or indirect affects of more livestock

� Improved productivity of livestock and riceproduction, and integration with fish culture,can reduce methane emissions

� Semi-intensive fish culture can improve effi-ciency of water use on-farm directly throughthe role of ponds and dams in the harvest,conservation and storage of rain and run-offwater

� Water consumption in aquaculture is relatedto both production of feed and the cultureenvironment. Semi-intensive systems havehigh feed-related efficiencies but more

environment-related losses compared to someintensive systems

� Biodiversity can be negatively or positivelyaffected by livestock-fish integrationdepending on its location relative to, anddependence on, natural water resources. Thespecies used (exotic/indigenous) and type ofculture system practiced will also affect biodi-versity

� Integration of livestock and fish can reducethe pressure on feed resources and the habi-tats which support them, through reductionsin, or contributions to, fishmeal supplies

� Drugs and other chemical used in livestockproduction can act directly or indirectly onaquatic systems, reducing opportunities forintegration with aquaculture. Cultured fish insurface water act as bio-indicators of thehealth of the aquatic environment

Summary of factors through which livestock and fish interact with theglobal environment

BOX 4.E

CHAPTER 5 • DESIGN CRITERIA FOR LIVESTOCK MANURED PONDS 61

Design criteria for livestock manured ponds

5

Practical designs of semi-intensive aquaculture systems

integrated with livestock are based on a range of factors. An understanding of the

dynamics of aquatic ecosystems is required to appreciate the mechanisms by which

fish grow in ponds receiving livestock wastes, and the constraints to their production.

Maintaining productivity of natural food growing in the fertilized pond and an

environment conducive to fish survival and growth have to be considered. The

principles of fertilization, well-established in terrestrial agriculture, have only recently

been adequately researched but the three dimensional aquatic environment offers a

range of options still to be thoroughly explored.

Intensification of fertilized systems through useof supplementary feeds is a well-known strategyin animal husbandry but, again, is unrefined foraquatic systems.

The characteristics of livestock wastesthemselves are also frequently unreported andunremarked but are critical to the design andmanagement of integrated systems. How wastesare used in fish culture systems also affectsefficiency and productivity of the system asexplored below.

Manured pond dynamics 5.1.1 OVERVIEW

Schaeperclaus (1933) first noted that static waterponds act as both ‘the stall and the pasture’ forfish capable of exploiting the web of natural feedstimulated by fertilization. In contrast toterrestrial systems managed for herbivores,

5.1


maintaining a balance between feeding andliving environments is both more complex andcritical. Whilst the concept of carrying capacityin terms of number, or biomass, of fish orlivestock that can grow per unit area is similar,the necessity to maintain adequate water quality,especially dissolved oxygen, is critical in aquaticsystems.

Ponds with optimal water quality but littlefood will be unproductive. Equally, food-richponds will under-perform or risk complete loss iflevels of the different feed organisms and fish, areexcessive and use up dissolved oxygen (DO).Both sanitary engineers and aquaculturescientists have quantified how wastes stimulatethe productivity of ponds through nutrientenrichment and how water quality changes

rapidly as a result. The diurnal cycle of DO thatoccurs in unfertilized systems becomes extremeas loading of nutrients increases. These swingsare mainly caused by photosynthetic productionand respiratory uptake of DO by dense blooms ofphytoplankton that develop after nutrientloading. Clearly, the key aspects of nutrientmanagement are to ensure that DO, and naturalfood levels remain adequate and in balancethroughout fish growth.

Many factors can affect the management ofwaste-fed ponds, which may have their origin atmacro-, local as well as micro- or pond level.Climatic and cultural factors can affect thepotential for integration of livestock and fishproduction at macro-level (Table 5.1). Nationalpolicies such as those relating to fertilizer and

Factors affecting use of animal wastes in ponds

Primary factors Secondary factors Ameliorating factors

Macro-level � Climate � Temperature � Seasonal production� Water availability � Irrigation

� Cultural � Tradition/aversion to use of wastes � Processing, treatment of fresh wastes � Education

� Availability of nutrients � Policye.g. concentrate feeds, � Infrastructureinorganic fertilizers

Local level � Site � Rainfall and water supply� Soils � Creation of turbidity.� Exposure � Acidity� Access for nutrients, seed, � Adsorption of nutrients into

management sediments� Competition for nutrients � Exposure to wind� Quality of nutrients � Sunshine, duration and intensity

Pond level � Pond design � Avoid deep (>3m) or � Frequency of waste addition shallow (<0.6m) water� Combination of size and � Polyculture and mixed

species of fish size stocking and � Harvest strategy harvesting may

optimize nutrientefficiency

TABLE 5.1


feed manufacture and import, can affectavailability and cost of nutrients at local level,supporting or undermining attempts to intensifylivestock and fish culture.

Local resource levels are also affected by bothphysical e.g. soils, topography, water availability,and social and economic factors that can foster orconstrain the development of integratedpractices. At the pond or plot level, design andmanagement of fish culture and associatedanimal husbandry have to balance resourceconstraints and opportunities.

Stable and high water temperatures andsunlight ensure year-round growth of both fishand their natural feeds. The tropics, in whichaverage monthly water temperatures remainabove 18°C, are ideal for culturing fish usinglivestock waste as inputs, although it is alsopracticed in sub-tropical and temperate climatesduring warmer periods of the year.

Manures can be used fresh, or afterprocessing, to enhance natural food production insun-lit ponds as much of the nutrient content offeed given to livestock is voided as excretory andfaecal waste. Although some nutrition may bederived directly from the waste, high-proteinnatural feed produced on the nutrients releasedfrom the wastes mainly in the form of plankton ismore important. Fish feeding low in the food web,e.g. carps and tilapias, benefit most from thistype of management since they can utilizeplankton, benthic and detrital food organismseffectively.

The nutrients contained in organic wastesstimulate a range of natural food organisms thatmay be suspended in the water column, attachedto substrates, or within the sediments. Sediment-water interfaces are key feeding niches for somefish species. The availability and value ofphytoplankton and bacteria, the dominantorganisms in most waste fed ponds, are linked tospecialized feeding habits of the fish. A variety ofcarps and tilapias can grow rapidly on suchnatural feeds alone, employing strategies similarto grazing (filter feeding) and browsing (ingestionof attached periphyton). A detritus-feedingniche, in which a large amount of sediment isingested, may also be important. Most fish areopportunistically inclined to consume macro-

invertebrates of various types, molluscs, insects,polychaete and oligochaete worms andcrustaceans.

Several factors affect the level of wasteloading and standing stock of fish that can besupported. The species of fish raised is importantboth from a perspective of varying feeding nicheand sensitivity to water quality, especially DO instatic water ponds without mechanical aeration.Carps are limited to standing stocks of <3 tonnesha-1 whereas tilapias may be harvested atstanding stocks of over 5 tonnes ha-1. Ponddesign, depth, shape and position also contributeto maintaining water quality since these factorsaffect exposure to wind, sunlight and run-off fromadjacent land.

The ‘carrying capacity’ of the fish pond, ormaximum biomass of fish that can raised in apond of given feed and water quality, can beenhanced by increasing fish density and usingfeed to supplement natural food. Supplementaryfeeds are generally relatively high in energy andlow in protein to balance protein-rich naturalfood.

Water quality, particularly the level of earlymorning DO, limits the amount of wastes thatcan be used. Under tropical conditions, inputlevels in excess of 100 kg dry matter (DM) ha-1 d-1

often ‘overload' the system over a typical fishculture cycle (4-8 months), causing early morningdeficits of DO (Figure 15). Balancing theproduction of wastes and the requirement of thefishpond is a key aspect of management (Colmanand Edwards, 1987; Knud Hansen, 1998). Anunderstanding of the livestock densities requiredto provide optimal loadings of nutrients for givenareas of fish ponds is key to the design ofmanure-fed systems.

The quality of livestock wastes used in fishculture varies greatly. The direct feeding value ofmanure is poor because of low levels ofmetabolisable energy and digestible protein(Wohlfarth and Schroeder, 1979). Any spilledlivestock feed mixed with the manure willincrease direct feed value. Nutrient compositionis a useful guide to the value of the waste as afertilizer, especially levels of total N and P; levelsof nutrient density as expressed as a ratio ofthese major nutrients with C (C:N:P) is also a


good indicator. However, these data may tell littleabout the availability or release of nutrients thatcan be taken up by the phytoplankton. The rate ofrelease of soluble N and P is useful for predictingmanure quality. A range of other benefits fromuse of animal manures in fish production havealso been identified (Box 5.A).

5.1.2 PRINCIPLES OF FERTILIZATION

High fish production in fertilized ponds is mainlyattributed to stimulation of autotrophicproduction, that is the growth of phytoplanktonthat filter-feeding fish can use directly as feed andwhich form a major proportion of the detritus inthe pond. Phytoplankton is also the main source ofDO in the pond. Both living and detritalphytoplankton are protein-rich and are the basis ofthe food web that can support the growth of arange of herbivorous and omnivorous fish.Technical and economic considerations determinehow fish ponds are best fertilized and managed.

Manure:

� Is a good source of N, P and C, the lattermay be limiting in rain-fed or other pondswith low alkalinities

� Can provide a substrate for zooplanktonproduction

� Can assist in clarification of clay turbidity inpond water

� Can reduce the rate of P adsorption intopond sediments if present as a layer at thesediment-water interface

� Can reduce seepage of pond water

� Can act as direct feed, especially for detri-tivorous fish

Source: Modified after Knud Hansen (1998)

Benefits of animal manures inpond culture

BOX 5.A

Mean dissolved oxygen (DO) in mg l-1 at dawn for ponds (200 m2) receiving differentlevels of manure loading. Error bars show standard deviations.

FIGURE 15

D O

(m

g l-1

)

Source: AIT (1986)

0 10 20 30(control) 80 160 240

10

9

8

7

6

5

4

3

2

1

0No. of ducks

Manure loading(kg DM ha-1 d-1)


NutrientsFertilization aims to supply the optimal level ofnutrients to stimulate phytoplankton production.Practically these nutrients are limited to N, P and C;other nutrients are required only in trace amountsand supplied by the fertilizer, supplementaryfeeding and the natural environment. Analysis ofthe nutrient content of healthy phytoplanktonindicates the level of requirement which is at aratio of approximately 50:10:1(C:N:P). The N:P ratiocan vary from <1.5:1 in N deficient algae to >15:1 inP-deficient algae. Carbon is often ignored but isrequired in the greatest amounts. Waste-fed pondsare seldom C limited because bacterial breakdownproduces carbon dioxide but inorganically fertilizedponds with low alkalinity often require lime toensure sufficient C. Molluscs can also drasticallyreduce C levels through removal of carbonate forshell growth.

Selecting fertilizers and fertilization rates tomeet the nutritional needs of phytoplakton oralgae has a history of confusion that recentresearch has clarified. Earlier studies, often usinglow densities of fish or stocking non-filter feedingfish, failed to show a clear relationship between Nand yields. Much of this research was based ontemperate lakes in which N fixation was importantin supporting the relatively low fish productivity. Itis now known that in warmwater freshwaterponds, N is usually the most limiting nutrient andthat high levels are required to optimize yields ofphytophagous fish such as Nile tilapia. Available Pcan also easily limit algal productivity as it israpidly fixed by various cations (Fe2+, Ca2+, Mg2+

and Al2+), and bound up in the sediments.Sediments with high clay content or containingacid-sulphate soils are particularly ‘greedy’.Fertilizer management should consider previous Pinputs or ‘pond history’; ponds used for aprolonged period and receiving nutrient inputswill require relatively less fertilizer.

This summary is based on the work of:Goldman (1979); Colman and Edwards (1987);Knud-Hansen (1998); Shrestha and Lin (1996);Knud-Hansen et al. (1991).

Fixed ratesThe use of fixed fertilization rates as guides tofarmers is based on experimentation at relatively

limited sites and cannot be simply extrapolatedto ponds everywhere. Moreover, most researchhas focused on a single phytophagous fish, theNile tilapia. A range of factors, includinglivestock and waste management systemsconsidered below, may affect fertilizationresponse. Differences in response by individualponds even located only a few metres apartindicate that fixed rates should be used only as aguide to avoid over or under-fertilization. Farmerscan use general guidelines, if presented in anappropriate way, and adapt them to meet theirindividual requirements. Indeed, farmers inChina and India learned to manage fertilizedfishponds before the principles were elucidatedby scientists. Clear explanations of how nutrientswork in the pond ecosystem are particularlyvaluable, as opposed to ‘recipes’.

There is generally concern among extensionstaff that excessive fertilizer levels, particularly ofN fertilizers, can result in fish mortalities.Generally this is more of a danger if fixed ratesare extended. A typical scenario is the effect ofsuch overloading during periods of lowtemperature or low light conditions when thecapacity of the pond ecosystem to absorb andutilize them is lower than normal. Whenconditions return to normal nutrients can then bepresent in surplus quantities causing dangerouslevels (see Box 5.B) or unstable phytoplanktonblooms that can ‘crash’ causing sudden declinesin DO and elevated levels of ammonia.

Animal wastes with unbalanced nutrientlevels, typically high C:N ratios and N:P ratioswell below optimal, are often compensated for byincreasing manuring rate. This can lead toreduced DO levels and fish growth (Box 5.C).

Detritus and periphytonThe availability and usefulness of very smallmicro-algae (nannoplankton; diameter < 10 µm)that tend to dominate waste-fed ponds and thediets of filter-feeding fish has been the subject ofmuch research. Mechanisms that describe theiringestion e.g. Northcott and Beveridge (1988),digestion (Moriarty, 1987) and avoidance oftoxins which they sometimes contain (Beveridgeet al., 1993) have been given.

The relative contributions of autotrophic and


heterotrophic pathways to the productivity offertilized fish ponds were once contested(Schroeder, 1977; Colman and Edwards, 1987).Most now conclude that algal-derived detritus,whether suspended, attached or settled is usuallythe dominant and most nutritionally valuableform of detritus available, even in waste-fedponds. It supports a huge range of zooplankton,substrate dwelling micro-invertebrates and fishdirectly. Non-filter feeding fish can still deriveadequate nutrition in waste-fed ponds byexploiting these feeding niches but the density atwhich their growth can be supported, thecarrying capacity, is correspondingly lower thanfor filter feeding species.

Fish that can graze ‘aufwuchs’, or attachedperiphyton, are less well supported inconventional fertilized ponds as substrate islimited. Recent studies indicate that increasedsubstrate availability can improve fish yields,especially if the substrate in enriched with

nutrients by soaking in manures. Periphyton-based aquaculture may be of particular benefitwhen size/scale of culture unit, or cost ofnutrients preclude conventional fertilization.Significant constraints include the availabilityand cost of substrate in rural areas wherebiomass is heavily exploited for fuel and otheruses.

Frequency of fertilizationFertilization, especially if fertilizers requiretransport to the pond, can be laborious and oftenresult in infrequent application of bulky animalwastes. In contrast, strategic livestockmanagement and system design can result insubstantial reductions of both costs for livestockwaste removal and fertilization of fish ponds(5.2.3). Integrated systems, in which wastescontinuously enter the fish pond and ‘feed’ thealgae probably result in optimal algae productivitysince nutrient depletion is least likely to occur

N and P loadings of 4 kg. ha-1d-1 and 2 kg. ha-1 d-1,respectively, were defined as optimal for tilapiamonocultures in a series of experiment using bothorganic and inorganic fertilizers at the AsianInstitute of Technology and other researchstations1.

Harvested yields of 4-5 tonnes. ha-1 of 200-250g fish in around 6 months are possible if 1fish. m-2 is stocked. Higher stocking densities (upto 5 fish. m-2) can increase net fish yields further.If smaller fish are acceptable and multiplestocking and harvest is practiced, netextrapolated yields of 12 tonnes. ha-1 year-1 arepossible.

Inorganic N fertilization in excess of these levelsresulted in :� total ammonia concentrations in pond water

(>1.5 mg/l), which at the typically high day-time pH levels (>9) lead to high levels of

toxic, unionized ammonia concentrations.

� possible effects of groundwater nitrate lev-els.

Optimal levels of N fertilization are already aboutfive times greater on an annual area basis thanthe maximum national average in Asia for land-based agriculture.

P fertilization needs may be lower thanrecommended if the sites where the P is adsorbedin pond sediments are filled. This may occurthrough:� previous heavy fertilization with P-containing

inputs;

� livestock manures with a relatively low N:Pratio;

� use of ricebran, containing high levels of P asa supplementary feed.

Fixed fertilization rates defined by experimentation

BOX 5.B

1 The Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/A CRSP) supported by USAID have undertaken research inHonduras, Rwanda and the Philippines andThailand.


(Knud Hansen, 1998). More occasional, heavierloadings are more likely to ‘shock’ the pondsystem, leading to explosive bacterial and algalgrowth and low early morning DO.

If fertilization adheres to fixed schedules,unbalanced nutrient levels may occur that do notmeet the needs of dynamic and unpredictablealga populations; algae in fish ponds are prone tospecies change or succession that impact onnutritional and water quality . During periods ofcontinuous rainfall, when static water ponds mayoverflow, the demand for nutrients may be higherand more frequent than dry periods for example.Thermal stratification also occurs, especially indeeper ponds that result in elevated nutrientslevels (Szyper and Lin, 1990). After breakdownduring heavy rain or wind, nutrients that haveaccumulated in the lower levels of the water andsediments are released, exceeding the pond’scapacity.

5.1.3 PRINCIPLES OF SUPPLEMENTARY FEEDING

Supplementary feeding has been a ratherneglected part of aquaculture science, perhapsdue to the intensive nature of most ‘modern’developed country aquaculture and its relianceon carnivorous fish species. However, the inten-sification of traditional aquaculture in Asia is

encouraging the use of supplements(Yakupitiyage, 1993; De Silva, 1993).

Supplementary feeding of a fertilized pondcan both increase the fish yield and reduce thetime to harvest but understanding howsupplements work compared to complete feeds iscritical. The provision of supplementary feed isrequired if fish of large individual size arerequired. Thus, although Nile tilapia of between200-250g can be produced on fertilizer alonewithin 5 months, individual growth thereafter isslow as natural feed alone does not meet optimalgrowth requirements (Edwards et al., 2000).

Supplements are generally used commerciallyif the use of complete feeds is uneconomic. Bothscientists and farmers are attempting to optimizetechnical and economic performance bydeveloping feeding strategies. These requireknowledge of local resource and marketopportunities.

Supplementary feed may also be requiredwhen conventional fertilization cannot beoptimized, if sufficient manure is unavailable, itsuse is unacceptable or high turbidity reducesphytoplankton productivity. Periods of heavyrainfall can make ‘green’ pond conditionsimpossible to maintain.

How supplementary feeds workFarmers providing supplementary feed to anystock, animals or fish, have a fundamentallydifferent aim to giving a ‘complete’ feed. Anintensively raised animal, for example a hen orsalmon raised in a cage, has negligible access tonatural feed of any type and must be given anutritionally balanced ration. In contrast, pasture-raised cattle or herbivorous fish require a feedthat can complement the low-cost terrestrial oraquatic, pasture respectively, most economically.When herbivorous fish eat only natural feed, partof the protein is used for energy, which could be‘spared’ by giving supplementary feed high inenergy. Furthermore, if natural feed is in shortsupply, especially as the density of filter-feedingfish increases, energy becomes limiting beforeprotein. This explains why energy-rich grainsand brans are commonly used in fertilized pondsand why, if fed alone or in ponds with little naturalfeed, they are nutritionally unbalanced and result

Ruminant manures from grazing buffalo had aC:N ratio of 26 and a N and P contents of 1.4percent and 0.2 percent DM, respectively.To achieve a loading of 4 kg N ha-1d-1, 300 kgDM. ha-1 d-1 of manure had to be loaded.

Dissolved oxygen quickly declined to dele-terious levels through a combination of:� bacterial decomposition of the dry matter;

� release of tannins from the manuresoccurred at high levels leading to;

� inhibited phytoplankton growth (<15mg/l).

Source: Edwards et al. (1994); Shevgoor et al. (1994)

High loadings of ruminant manure

BOX 5.C


in poor growth. Extending this concept of‘limiting nutrients’ by developing supplementaryfeeds that will support growth in static-watersystems at higher fish densities has become ofgreat commercial significance (Edwards, 1999).

Timing of supplementary feedThe low value of many freshwater pond fish maymake supplementary feeding throughout theproduction cycle unattractive. Use of formulatedfeeds is still relatively uncommon unless the fishare relatively high value carnivorous species ordestined for local luxury or export markets indeveloping countries, even if they are available.Strategic feeding of low-cost supplements ismost cost effective at the beginning and end ofthe fish culture cycle.

Fish seed are a valued-added product forwhich economic, complete feeds have beenunavailable but for which supplementary feedingis now the norm. Juvenile production of mostfreshwater species, in which hatchlings areraised to finger-sized fish ready to stock into on-growing ponds to produce table-size fish isnormally undertaken in zooplankton-rich, earthenponds. Even species that are herbivorous later inlife require a diet high in crude protein andsupplementary feeding, especially if high qualityingredients are used, allows much higherdensities of fingerlings to be ‘nursed’ tomarketable size. High survival and quick turnoverof stocks is essential for most nursery operationsand supplementary feeding tends to improvereturns compared to fertilization alone.

The fattening of table fish is a strategic optionmuch employed in livestock production but littleresearched in fish culture. Conceptually themethod may have application for a range of fishspecies, but especially those that can ‘graze’until the size when feeding becomes economic.Fattening will often be most cost effective incages; the origins of cage culture were probablythe fattening of undersized and less valuable,wild fish before marketing. Feeding high qualitypellets as a supplementary ration in tilapiamonocultures has been found to be most cost-effective if limited to fish that have attained 100-150 g after 3 months pond culture based onfertilization alone (Diana et al., 1996).

Feeding levelsFeeding of readily available by-products such asricebran in fertilized ponds can be cost effective,but even cheap feeds can reduce returnscompared to fertilization alone if optimal levelsare exceeded. Rice bran boosted yields of a Niletilapia monoculture receiving egg-laying duckmanure by between 10-150 percent (AIT, 1986),but its use may not be cost effective. The ‘law ofdiminishing returns’ was demonstrated when alow feeding rate (1 percent body weight day-1)increased yields, profitably by between 28 and 40percent, for two levels of duck manure loading,but doubling feeding rate (2 percent) increasedyields by a mere 4 percent or reduced them by 16percent respectively (Yakupitiyage et al., 1991).This situation demonstrates that overall drymatter inputs into ponds must be carefullycontrolled in waste plus supplementary-fedsystems or poor water quality can undermineyield improvements through improved nutrition.Feeding levels of grown tilapia (100-150g) can bereduced to 50 percent of satiation without adecline in individual growth (Diana et al., 1994).

Non-filter feeding fishCarp farmers optimize the productivity ofpolycultures in India by strategic use of home-mixed, supplementary feeds in ponds receivingboth poultry manure and inorganic fertilizers.Fish are stocked as stunted seed, trained to feedfrom plastic fertilizer bags with holes at the base.Optimal profitability has been achieved bydoubling rates of fertilization over official recom-mendations (Nandeesha, 1993). The relativescarcity of benthic organisms make the energysparing effect of supplementary feeds particularlyvaluable for benthic-feeding carps (Yakupitiyage,1993); this may explain why the effect ofsupplementary feed is less pronounced for filterfeeders in phytoplankton-rich water.

Supplements to complement natural food Supplementary feed should complementlimitations in the natural food present in thesystem. Critical standing crop (CSC) identifiesthe biomass of fish at which growth is retardeddue to poor nutrition (Hepher, 1988). Tacon and


De Silva (1997) have incorporated the standingcrop of fish and natural food into the concept(Figure 16). Edwards et al. (2000) propose thatsupplementary feeding be classified into fourstages. Research on Nile tilapia clearly indicatedthat only vitamins and minerals (excluding P) didnot affect performance as indicated by growthand body composition (Box 5.D).

Supplementary feed under conditionsof lack of natural feedFarmers with turbid water ponds that do notrespond to fertilization typically have poor resultswith supplementary feed alone. The problem isparticularly common during the rainy season inponds with unstable dikes. Fertilizers may also bewashed out as ponds overflow under suchconditions. Yields from ponds fertilized daily withinorganics alone at optimal levels (4 kg N and 2kg P ha-1 day-1) were compared with using theequivalent amount of cash to purchase pelletedfeed, rice bran or cassava chips. Pelleted feedsgave the best result but the researchersrecommended farmers to use equal costedamounts of inorganic fertilizers and commercial

pelleted feeds under such conditions (Edwards et al., 2000).

Waste characteristics5.2.1 GENERAL CONSIDERATIONS

Manures contain considerable amounts ofvaluable nutrients for recycling through aquaticfood webs to produce fish. Both the total amountand the proportion of nutrients available can behighly variable. Between 72-79 percent of the N,61-87 percent of the P and 82-92 percent of thepotassium in the diet was present in the waste offeedlot, egg-laying hens (Taiganides, 1978)indicating the scale of the resource. Generally thewastes from monogastric animals (pigs andpoultry) are more nutrient-dense than wastesfrom grazing ruminants but the range ofruminant waste quality varies enormously (Table5.2). Solid manure will often be mixed with avariety of other fractions such as urine, bedding,washing water and waste feed.

5.2

Schematic depiction of changes in the natural food organisms and fish yields, in relationto standing crop of the cultured organism and the ensuing protein needs of the supplemental feed (s)

FIGURE 16

NFS

Y

CSC

Standing crop Source: Tacon and De Silva (1997)

Rat

e of

incr

ease

in y

ield

(Y

) an

d n

atur

al f

ood

sup

ply

(N

FS)

Increasing protein level

in food


Species, size and sex also affect the quantityof animal manure produced. Husbandry level andwaste management techniques can also greatlyaffect waste collection and use in fish culture.Complete collection of wastes may be impracticalor costly, particularly for livestock raised underextensive or semi-confined conditions. Some-times wastes cannot be used immediately,necessitating processing and/or storage and thiswill also affect their nutrient content. The

quantity of waste produced by any animal isrelated to body weight, and thus any growthduring a production cycle affects the design oflivestock-fish systems. The availability of solublenutrients from wastes of different types alsoaffects their value, and is often related to age andoriginal quality of the manure. Any calculation ofthe number of livestock required to optimise agiven area of fishpond therefore needs toconsider a wide range of variables.

Stage Category Limited Enhanced natural feed natural feed Notes

1 No supplementary feed X Water may also be turbid2 Energy-rich feed XX e.g. rice bran (dry, wet mash) 3 Energy-rich feed + some

building blocks X XXX e.g. soybean cake and noodle-waste(wet dough, pellet)

4 Energy-rich feed + some building blocks + catalysers XX XXX Di-calcium phosphate (DCP),

salt (often pelleted)5 Complete feed XXX XXX Balanced amino and fatty acids,

vitamins, minerals, and attractants (pelleted)

X - XXX; least to most important

Categories of supplementary feeding

BOX 5.D

� Green et al. (1994) found no benefits to yieldsin poultry-manure fertilized ponds that alsoreceived high-quality pelleted feed. This canbe explained by the growth of the fish beingsupported by natural feed alone at the lowdensities used (2 fish. m-2).

� Yields may also be constrained by other fac-tors such as seasonally low temperature andDO levels. The relatively low yields (1.5-4.7tonnes.ha-1 year-1), reported in Hong Kong bySin (1980) despite supplementary feeding ofcarp polycultures fertilized with duck manure,appear to be related to such water quality fac-

tors. Green et al. (1994) also reported pooreryields in supplementary-fed, poultry waste-fertilized ponds during cooler periods.

� Since supplementary feeding works by com-plementing natural feed, if there is little natu-ral feed, supplements are ineffective. Suchcan be the case in clear, plankton-poor envi-ronments such as occur when farmers close towater supplies allow constant exchange ofwater or when high levels of silt turbidityreduces transparency, and productivity ofplankton.

Disappointing results with supplementary feeding

BOX 5.E


5.2.2 SPECIES, SIZE AND SEX

Livestock waste output is often described interms of nutrients available. unit body weight-1

(g nutrient.animal unit-1 day-1). This can varygreatly within the same species or strainmanaged under different conditions but formonogastrics raised on formulated diets underintensive conditions is relatively predictable.Relative waste production (g. kg live wt.-1)declines with age and size and food requirementalso change. Thus more, smaller animals willgenerally produce more and higher quality wastethan the same biomass of larger animals of thesame type. Breeding animals fed high quality butrestricted rations tend to produce smallerquantities of nutrient-rich manure than animalsbeing fattened ab libitum. Monogastrics fedcomplete formulated diets have nutrient-richwastes whereas ruminants fed fibre-rich feedproduce wastes relatively high in dry matter, butpoor in N and P. The large individual size of mostruminants means that outputs of total N and Pper animal can be substantial. Low nutrientdensity and presence of tannins negatively affectthe value of ruminant faecal wastes inaquaculture, reducing its value as pond fertilizers

compared to that suggested in actual levels of Nand P. However, intensification throughconfinement and improved feeding can improvethe availability and quality of wastes.

The diverse nutritional needs of egg-layingand meat breeds of poultry also greatly affectmanure composition. The calcium and P-richexcreta of laying birds reflect diets designed tosupport egg-shell development and the high fibrecontent in waste of juvenile (replacement) layingbirds fed reflects the content of fibre in their diet.The considerable proportion of total N found inurine and washing water (Figure 17), as opposedto solids has important implications for theirmanagement. Generally urine contains little P,except for pigs.

5.2.3 FEED AND WASTE MANAGEMENT

Feedlot, scavenging and intermediate systemsLivestock managed outside of feedlots have morevariable waste characteristics and generally lessof the nutrients produced can be collected.Animals that are stalled some or all of the time,and fed cut-and-carried forages and/or

� Natural food produced through fertilizationalone can support cost-effective production ofherbivorous and omnivorous fish

� The production of natural feed and mainte-nance of water quality need to be balanced infertilized ponds

� Phytoplankton are usually the most importantsource of natural food and DO

� Plankton-derived detritus can be an importantsource of food for fish; lack of substrate limitsthe importance of periphyton in conventionalsystems

� The ratio of major nutrients in organic wastes(C, N, P) characterizes their quality and valuefor fish culture

� Fixed fertilization rates can be used as a guideto required levels but optimal strategiesrequire adjustment for local and seasonal vari-ation

� In general ‘little and often’ reduce risk of‘overloading’ the pond and enhances efficien-cy of nutrient use

� Supplementary feeds can improve the viabili-ty of fertilized systems under many conditions

� High levels of natural feeds, temperature andother physical factors remaining within thenormal range, and appropriate densities ofsuitable fish species stocked are key criteria

Summary of key factors affecting manured pond dynamics

BOX 5.F


Input and output of poultry waste fed-aquaculture

Inputs (g m-2 day-1) Output (g fish m-2 day-1)System Poultry waste Other Fish

DM N P DM N P

FeedlotEgg-laying ducks 6.71 0.3 0.07 - - - Tilapia 2.82 200 m2 ponds, 6 months

(Edwards et al., 1983)Broiler chickens 10.0 0.4 0.46 - - - Tilapia, 2.87 400 m2 ponds, 3 months

Common carp (Hopkins and Cruz, 1982)Layer chicken 14.3 0.4 0.3 - - - Tilapia 1.33 1 000 m2 ponds, 5 months

(Green et al., 1994)Layer chicken 1.07 0.03 0.018 - 0.47 0.23 Tilapia 2.75 220 m2 ponds, 5 months

(Knud-Hansen et al., 1991)ScavengingMuscovy duck 9.7 0.15 0.10 - - - Tilapia 1.38 5 m2 tanks, 3 months ; ducks fed

75 percent ad libitum (AFE, 1992)Egg-laying duck 3.0 0.23 0.03 - 0.17 - Tilapia 1.21 200 m2 ponds, 4 months

(AASP, 1996): rice branEgg-laying duck 1.24 0.20 0.01 - 0.17 - Tilapia 0.53 200 m2 ponds, 4 months

(AASP, 1996): paddy rice

Source: Little and Satapornvanit (1996)

TABLE 5.2

Annual production of nitrogen in faeces and urine for various livestock

FIGURE 17

Urine

Faeces

Source: Modified from FAO (1980)1 values for 10 broiler chickens

25000

20000

15000

10000

5000

0

g N

Yea

r -1

Broiler chicken1 Pig Dairy cow Beef


concentrates, tend to show both increasedproductivity and produce wastes of higherquality and collectability (Box 5.G).

Feed qualityQuality of feed greatly affects both livestockperformance and waste quality for aquaculture.However, there are few data for fish yieldsderived from pig production other than fromcomplete balanced diets. An exception is Long(1995) who found that although fattening hybridpigs fed only cooked village ricebran andchopped water hyacinth grew at half the rate ofpigs fed balanced rations, their waste could stillsupport extrapolated fish yields (more than 4tonnes ha-1 year-1) higher than the norm in theMekong Delta.

Performance and waste availability of semi-feedlot poultry have also been little studied butpreliminary research is encouraging. Inscavenging poultry, manure quality is greatlyaffected by the quality and quantity ofsupplementary feeds, which in turn affects fishproduction. Compared to confined birds fedcomplete diets, nutrients in the waste are low,resulting in poorer performance of fish raised on

the waste (Box 5.H; Table 5.2). However, usingmore waste from a larger flock of ducks cancompensate for the smaller amount of lowerquality manure produced per duck fromscavenging birds penned for supplementaryfeeding and waste collection only at night.

There are tradeoffs between benefits tolivestock and fish regarding the type ofsupplementary livestock feed used. Egg-layingducks (Khaki Campbell x local hybrids) fed paddygrain at night produced poorer quality manurethan those fed rice bran. The amount of N and Pin the manure was 50 percent and 25 percent,respectively, of that found in ducks fed relativelynutrient-dense, village rice bran. Fish yieldsreflected these different nutrient inputs, withricebran-derived fish yields being almost doublethose from paddy-fed ducks. However, thenumber of eggs produced was significantlyhigher for ducks fed paddy rice compared toricebran (Figure 19).

Total collectable nutrients in the waste canexceed that present in the feed given as a night–time supplement. Natural food scavengedduring the day is usually of higher food value thanthe supplement (Box 5.H and Box 5.J).

� A range of goat management options wascompared with respect to system outputcharacterized by goat performance and nutri-ent collection. Zero-grazed Katjang meatgoats fed grasses, tree legume leaf and rice-bran were managed alongside animals teth-ered for day-time grazing and receiving a con-centrate (ricebran) or cut legume supplementduring night-time confinement. Theseoptions were compared to goats that werealso tethered but had no supplementary feed.The supplementary use of leguminous leavesparticularly improved the collectable N inwastes, almost to the level of zero-grazed ani-mals. Liquid wastes (urine plus washingwater) contain about half of the N produced

and this could be used to totally replace inor-ganic N in fish production. Using ricebran asa supplementary feed enhanced P levels inthe waste.

� The importance of frequent waste collectionwas also compared in tethered animals with nosupplementary feeding. The frequency ofwaste removal affects both the amount of col-lectable nutrients and animal productivity.Goats stalled overnight on infrequentlyreplaced bedding show reduced productivityand the amount of nutrients collected, particu-larly N, are reduced substantially compared todaily cleaning and waste collection (Figure 18).


Goat management level affects nutrients collectable for aquaculture

BOX 5.G


Goat production and total collectable nutrients in different management systems

FIGURE 18

Goat production

Nitrogen

Phosphorous


Egg laying rate of Khaki-Campbell x local strain ducks fed two different supplementarydiets, T1=unhulled paddy rice and T2=village rice bran

FIGURE 19

T1T2

Live

wei

ght

gain

(g

head

-1d

ay-1

)

Production systems

Tota

l col

lect

able

nut

rien

ts (

mg

kg B

W-1

day

-1)

120

100

80

60

40

20

0

500

400

300

200

100

01 2 3 4 5

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24Weeks

100

90

80

70

60

50

40

30

20

10

0

Layi

ng r

ate

( p

erce

nt)


Ten approaches were compared for themanagement of lowland rice-fields; conventionalrice monoculture, conventional rice-fish culture,rice monoculture, rice-fish, rice-azolla, rice-duck,rice-fish-azolla, rice-fish-duck, rice-azolla-duckand rice-fish-azolla-duck. Pesticides were onlyused in the conventional treatments. In additionto an improved understanding of the specificinterrelationships within such complex systems,the study highlighted the potential benefits ofintegration to the stability of rice productionecosystems.Key findings included� Rice productivity in rice-fish systems were

similar to controls but enhanced when bothducks (24-35 percent) and azolla (38-42 per-cent) were integrated.

� Production of Nile tilapia was increased by afactor of 0.33 with use of azolla, 1.9 withducks and 2.2 with both. The relative impactof both azolla and ducks on the fertility of thesystems also correlated with changes inoligochaete densities in ricefield soil samples.

� Egg-laying ducks raised at a density of 400 ha-1

were housed in pens over refuges within rice-field plots at a ratio of 12 female:male to pro-duce fertile eggs (balut). The ducks wereallowed to scavenge in the ricefield plot prior

to rice transplantation and for periodsbetween transplantation and flowering. Duckswere fed a commercial layer ration that wasreduced by between 10-30 percent during thescavenging periods. Laying rates dropped dur-ing periods when ducks were released in thericeplots but averaged over 60 percent duringthe total 482 days of the trial.The presence ofazolla had no effect on laying rate.

� Integration with ducks increased investmentcosts substantially but also yielded the high-est net returns and improved income distribu-tion through the year.

� High production costs (N-azolla was 10 timesthe cost of inorganic N), reduced the econom-ic benefits of using azolla in rice production,but integration with fish and ducks improvedreturns.

� Ducks had significant effects on control of thegolden apple snail if allowed to scavenge inricefields pre-transplantation, especially gold-en apple snail.

� Azolla and ducks reduced total weed abun-dance by 60 and 49 percent respectively.

� Nile tilapia was ineffective at controlling snailsor weeds and pond refuges appeared toincrease their persistence.

Integration of duck and fish production in ricefields in the Philippines

BOX 5.I

� Restricted feeding with rice bran duringnight-time confinement of muscovy ducks(Cairhina moschata) allowed to scavenge dur-ing the day reduced both the quantity andquality of collectable wastes. The level oftotal N in wastes declined with the level ofrestricted feed given from 1.28 g N duck-1

day-1, for birds fed ad libitum to 0.65 g Nduck-1 day-1 for ducks restricted to 50 percentof ad libitum feeding levels (AFE, 1992).

� Effects of both duck diet and the waste load-ing on fish growth were clear. A higher wasteloading of ducks fed on the most restricteddiets (50 percent of voluntary level) was asvaluable for fish culture as less waste fromducks fed on a voluntary basis. Fish growthwas similar to that from fish receiving wastefrom feedlot egg-laying ducks at a lowerstocking density, though inferior to a pellet-fed treatment.

Quantity of supplementary feed affects scavenging poultry wastes andfish production

BOX 5.H

Source: Cagauan (1999)

Herding of ducks in ricefields typicallyreduces the input of wastes into associated pondfish production systems. However extensivemanagement of ducks remains a popular systemin many places and can be integrated with fishproduction within the ricefield itself. Cagauan(1999) investigated the productivity of rice, ducksand fish (Oreochromis niloticus) withinexperimental integrated systems in CentralLuzon, Philippines. The management of thehybrid aquatic fern (Azolla microphylla Kaulf. xAzolla filiculoides) was also investigated for itsimpact on fish and duck productivity andprevalence of weeds and Golden Apple snail(Pomacea canaliculata Lam.) in ricefields (Box 5.I).

Spilled feedSpilled feed is a loss to the livestock productionsystem but a gain to the fish because of its directfeeding value. The timing, frequency andlocation of feeding affect the amount of spilledfeed and its direct value to fish. Feedpresentation and composition, availability anddesign of water containers and livestock type allaffect the amount or proportion of spilled feed incollectable wastes. Feedlot ducks fed completediets appear to waste less than birds allowed toscavenge during the day and given access tosupplementary feed at night. Feed processingcan reduce spillage; up to 15 percent ofgranulated feeds may be lost compared to 10 per-cent if the same duck feed is pelletised (Barash etal., 1982). Ad libitum feeding of all livestockincreases spillage losses and feeder and watererdesigns are important to minimize losses.

Feeding behaviour and the nature of differentfeeds may increase the amounts of feed availabledirectly for fish. Waste feed left in the watercontainer comprised more than 25 percent of thecollectable dry matter from scavenging muscovyducks fed a supplement of village rice bran(AASP, 1996).

5.2.4 NUTRIENT RELEASE FROMMANURES

Nutrients contained in manure are notnecessarily available for uptake by the food webin the pond. Indeed only a fraction is usuallyreleased in a soluble organic form, usually withinthe first few days of adding the waste to the pond(Knud Hansen, 1998). Cumulative nutrientrelease curves for buffalo and duck manureindicate that the nutrients within manure frompoorly-fed ruminants are relatively unavailablecompared to monogastrics fed high quality feed.Manures with high levels of material resistant todecomposition may quickly build up in thesediments, requiring frequent removal.

5.2.5 WASTE COLLECTION ANDSTORAGE

Animal waste quality can be drastically affectedby the method of collection and storage prior to


� In a comparison of three different supple-mentary feeds (village rice bran, groundmaize and ground sorghum) fed to pekinand muscovy ducks, both waste quantityand quality were affected.

� The degree of wastage, related to palatabili-ty and physical attributes of the feed, wasan important factor but the intake and prox-imate composition greatly affected the valueof waste for fish culture.

� Manures derived from maize-fed ducks werehigh in N, sorghum were intermediate andrice bran low reflecting the composition ofthe feeds themselves.

� Muscovy ducks were allowed to scavengeduring the day and then fed one of three lev-els of a village rice bran ration while con-fined at night. Levels of nutrient in thewaste were related to the amount of feedconsumed. Khaki Campbell egg-layingducks fed a complete diet while confinedproduced greater quantities of nutrient-richwaste (Figure 20).

Source: Naing (1990)

Impacts of supplementary feedquality on waste characteristics

BOX 5.J


Dry matter (DM), total nitrogen (N) and total phosphorous (P) in wastes of ducks

FIGURE 20

50, 75, 100 were levels of restricted feeding as a percentage of voluntary intake in scavenging ducks confined and fed village rice bran at night. KC: Khaki Campbell hybrid egg-laying strain fed a

complete diet under total confinementSource: Modified from FAO (1997a)

100 75 50 KC

120

100

80

60

40

20

0

4

3.5

3

2.5

2

1.5

1

0.25

0

DM

N

P

Dry

mat

ter

(g d

uck

-1 d

ay-1

)

N/P

(g

duc

k -1

day

-1)

Loss of total nitrogen in fresh layer manure with time

FIGURE 21

Storage duration (weeks)

Source: Flegal et. al. (1972) in FAO (1980)

1 2 3 4 5 6 7 8 9 10 11 12 13 14

6

5

4

3

2

1

0

Tota

l nit

roge

n (g

)

its use in fish culture. Bedding materials andwashing water have particular influence oncomposition of manures, but storage conditionand duration also affect their value.

The use of litter or bedding is a key part ofintensive livestock husbandry. High densities ofanimals can be kept in good health as litterabsorbs moisture, reduces odor and ammoniaand provides a soft floor surface. Typicallybedding increases dry matter, ash, fibre andcrude protein in the manure. Litter is a livingcommunity of detritus and microorganisms thatvaries in quality with type of substrate, livestockand its management. Fermentation occurs overtime and results in losses of N, volatalized asammonia or becoming refractory and unavailable.The concentration of some vitamins mayincrease (vitamin B12) and some antibiotics (e.g.chlortetracycline) decrease with duration ofstorage (Chapman, 1994).

The steady decline in nutrient content ofmanures not collected on litter during storage isaccelerated if wastes are stored under conditionsof high temperature and/or exposed to wind andrain (Figure 21).

The needs of fish production for waste inputmay vary through the year and/or not matchwaste production by the livestock throughout theentire production cycle. Thus, removal andstorage for later use, or sale or use elsewhere onthe farm may be required. A storage pit is acommon feature on Chinese integrated farmsallowing strategic use of manure and preventionof overloading during seasonally cool periods.

Processing of waste, particularly throughanaerobic fermentation to produce biogas, canresult in concentration of nutrients as C is lost.This option has been promoted as a method ofreducing waste volume and increasing its valuefor fish culture. The reduction of BOD in wasteduring anaerobic fermentation means thatassociated aquaculture can process the wastes ofgreater numbers of livestock.

Overall evidence suggests that both aerobicand anaerobic storage of livestock wastesreduces their net value. Aerobic compostingresults in losses of N as ammonia, whereasalthough anaerobic fermentation concentrates N,

much of it is ‘bound-up’ or refractory and notreadily available for use by organisms in thepond’s food web.

Lekasi et al. (2001) assessed manuremanagement in the Kenya Highlands and foundit to be critical for sustaining livelihoods oflivestock-dependent people. Smallholder dairyingwas particularly important and the major conduitfor import of external nutrients onto farmsthrough purchase of feeds and supplements.Farmers had many ideas for the bettermanagement of manures but few wereimplementing them, especially urineconservation. Manures were also bought and soldat prices above their nutrient value alone,indicating the value farmers placed on thephysical benefits to soil quality.


� Manures contain a large proportion of thenutrients in livestock feed

� Species, size and sex of livestock can dra-matically affect the amount of manure pro-duced by livestock

� Characteristics of collectable livestockwastes are affected by many factors butlevel and quality of livestock feed are mostimportant

� Mixing of faecal and excretory waste withbedding or water tend to decrease nutrientdensity

� Wastes from scavenging livestock fed sup-plementary feed during night-time confine-ment can approach the value of feedlot-derived wastes for aquaculture

� Storage, especially under aerobic and hightemperature conditions, leads to loss of N

� The value of fermentation or compostingof livestock wastes on farm before use foraquaculture is often impractical and bringsfew advantages.

Summary of factors affecting livestock waste characteristics

BOX 5.K


5.3 WASTE ADDITION

Maintaining optimal levels of nutrients and waterquality condition to meet the needs of pond foodweb organisms, fish and other components of thefarming system requires an understanding andapplication of basic concepts rather than arecipe. Best fertilization practice is rarely basedon fixed levels of nutrient inputs (or numbers oflivestock per area of pond) because both therequirement of the fish culture system and theavailability of waste are likely to vary.Nevertheless, for the tropics, upper levels ofanimal numbers per unit area of fish pond can begiven, assuming standard feeds and size oflivestock and, a need to maintain aerobicconditions (Little and Muir, 1987).

Systems designed for easy removal and use oflivestock wastes, allow the most completeintegration of livestock with fish, resulting in theleast loss of nutrients and their most efficient usein aquaculture.

Livestock pens should be designed for easycollection and removal of wastes as well as high

performance of the animal. The design andmaterials should allow for quick and completecleaning and reduce exposure of wastes to directsunlight, wind and rain. Livestock should beconfined in a way that does not allow damage tothe pond dikes. Allowing swimming birds andwallowing ruminants access to the pond dikescan result in rapid deterioration to pondstructure, turbid water and loss of manure.Reinforcement of dikes with brick, concrete andsynthetic sheet has been tried to prevent damagewith limited impact in many cases. Limitingducks to a cleanable pen and water surface isdesirable.

Collection of urine, especially for ruminants isoften overlooked and yet it contains aconsiderable proportion of the N. Cracked orbadly designed floors of pens, although stillallowing continued collection of manure, resultsin losses of urine.

Close proximity of the pen and fish pondgenerally results in more consistent transfer ofwastes from livestock to pond. Sometimes penscan be situated over ponds, allowing constant

ABOVE

Backyard pig production in Northeast Thailand has beenlimited to households who can obtain sufficient rice by-products. Greater availability of complete feeds and bettertransportation systems is opening up further opportunitiesfor backyard production

RIGHT

Washing waste duck feed from the waterer into fishpondsnearby. This is a high quality pond input


Effect of feeding and management on waste characteristics of livestock

System Feed ProductionPoultry Feed lot Scavenging Complete Supple- Daily live Laying rate DM

mentary W. gain ( percent)(g/d)

Egg laying duck Yes No Yes No 1.88 46-58 44.7

Egg laying chicken Yes No Yes No - - 44

Broiler chicken Yes No Yes No 32 - 20

Egg laying duck No Yes No Yes 0.38 16.3 59.9

Egg laying duck No Yes No Yes 0.42 29.8 24.8

Muscovy duck No Yes No Yes 10.4-16 - 40-70

Mean values for ducks on a range of dietary regimes; includes nutrients in manure, dry and wet

waste feed

Muscovy duck Yes No Yes No Male 32 33

Female 20 - 24

Growing pig Pigs fattened on cooked rice byproducts and water hyacinth; values include manure, urine and

washing water

Yes No Yes No 370 - 1400

Goats Based on replicate Katjang goats (n=3) of between 17-30 kg initial weight over a three

month period. Wastes removed daily unless otherwise stated

yes No Yes No 106 453

yes Yes No Yes 62 256

yes Yes No Yes 69 266

yes Yes No No 35 167

Yes Yes No No 16.7 200

TABLE 5.3

Protecting the dikes ofduck-fish ponds fromdamage using fences andramps to allow access tothe water


addition of waste to the pond used, which mayoptimize fertilization. High land costs andavailability of suitable building materials andexpertise are the norm for this type of system.The disadvantages include difficulties in accessto both livestock and fish and in controlling wasteinputs to the levels required as well as higherconstruction costs, particularly for pigs and largeruminants. Household pigpens in NorthernViet Nam are a major source of manure for thewhole farming system. Situating the pen, withwell-sloped floors and pipes close to small fishponds, allows urine to be recycled immediatelywith little loss of N, and strategic use of solid

waste in field crops and horticulture. Location oflivestock pens close to fish ponds should considersecurity, all-weather access and gooddistribution of wastes in the pond.

Transfer of wastes away from peri-urbanareas where land costs are high, to areas wherefishponds can be larger and waste use moreefficient, can be an advantage. Additionally, itcan provide opportunities for poorer people tobenefit as waste traders.

In situations where land costs are high andair-breathing fish can be economically raised,farmers may seek to exceed the normal density oflivestock per unit area of pond. Alternatively they

Waste (g/animal/day)N P

1.97 0.49 Edwards et al. (1983)

1.3 1.14 FAO (1980)

0.7 0.92 Hopkins and Cruz (1982)

1.16 0.69 AASP (1996) (rice bran)

0.52 0.16 AASP (1996) (Paddy rice)

0.65-1.28 0.5-0.8 AFE (1992)

Khalil, (1989)

1.65 0.71

1.24 0.55

Long (1995)

29.1 13.6

Little and Edwards (1999)

7.84 3.47 Stall fed, ricebran and legume

fodders

5.12 2.27 Grazing+ricebran

8.08 0.74 Grazing+legume fodder

4.57 0.57 Grazing only

1.27 0.41 Grazing only; irregular waste

removal

Collecting manure from underneath roosts of villagechickens for use in fishponds. Greater frequency ofwaste collection increase both the quantity andquality of collectable wastes


� On first entering the duck-fish farm of MrPornsak it appears that duck densities arerather high for the area of ponds (<5000 m2)on the farm. Closer observation reveals thatprobably very little of the manure producedby the ducks is entering the ponds and thatlarge amounts of extra feed are being given tothe fish in the system.

� The operation fattens, holds and slaughtersmeat ducks (Pekin and Cherry Valley) espe-cially for the restaurant trade. Between15 000-30 000 ducks are on the farm at anytime.The ducks are purchased in large flocksfrom rice farmers who have raised them byherding them through rice fields immediate-ly after harvest for around 70 days. Theyhave grown fast but now need to be fat-tened intensively in a feedlot; high qualitycomplete feeds are given for just a fewweeks in the covered sheds that gives theducks access to the fish ponds, which arereally borrow pits. In this area of formerricefields, the land must be raised to allowconstruction of buildings, leaving deepenedareas next to the duck houses that can bestocked with fish.

� Mr Pornsak’s main source of income is his dailydirect sales of ducks to restaurants; income fromfish is only an annual bonus and he thereforekeeps his system simple. He chooses to sell mostof his duck manure that rapidly builds up in hisdensely stocked feedlot to neighbouring fruitfarmers. The amount of duck manure wouldgreatly exceed that required to fertilize his limit-ed area of fishponds for low-value herbivorousfish. He therefore stocks a species of carnivorousriver catfish (Pangasius hypophthlamus), thatcan be raised at high density and is tolerant ofpoor water quality. They require feeding to reachmarketable size (>1 kg) within a year and dispos-ing of whole ducks that die before they reach themarket size in the fishpond is convenient. MrPornsak has no harvest equipment and thereforesells the fish to middlemen who drain the pondsand harvest his fish annually; he receives a fixedprice per kilogram. Only a small proportion oftotal income is derived from the fish componentof the farm (<2 percent), compared to processedducks (88 percent) and feathers (10 percent).Manure sales bring negligible returns but thecharacteristics of the operation prevent more on-farm recycling of manure to fish.

Pornsak’s duck slaughterhouse in Bang Lane, Central Thailand

BOX 5.L

LEFT

Large integrated meat duck-fish ponds in Taiwan are lined with bricks to reduce erosion of the dikes

RIGHT

Pigs being cooled and pens being washed down; water from fishponds is used for this task and the enriched waterruns via drains back to the fish pond


may add feeds or fertilizers to supplement animalproduction wastes (Box 5.L). More normallylivestock waste is insufficient to optimize fishproduction, because of risks or costs associatedwith intensive livestock husbandry or problemsmanaging the waste or because of the limitedresources of small-holders.

When livestock and fish are raised within a

broader farming system, experienced farmersdesign the integration to more closely matchtheir overall needs. The cost of complete nutrientcollection may be too high. Concrete floors thatallow collection of urine and washing water maynot be affordable, or the high cost of nutrientsmay require manures to be used elsewhere on thefarm (Box 5.M).

Lung Surin integrates a flock of 1500 egg-layingducks with fish and fruit production on his farm inNakon Pathum, Thailand. He chooses to use duckmanure relatively extensively for fish culture(total area of ponds more than 2 ha) rather thanoptimize the production of fish alone. Hisstrategy allows him to reduce the productioncosts of eggs, maintain duck health and also touse manure for horticulture. Rice is doublecropped in the area, presenting opportunitiesseveral times in the year to suspend completefeeding and allow ducks to forage for food at lowcost in the surrounding fields. The ducks alsoscavenge in the margins of the very large pondsyear-round, which maintains their condition.

Ducks raised in feedlots at high density are moreprone to stress-related illness. In addition to thenatural feed that the ducks scavenge, heoptimizes egg production through using a highquality feed that he mixes himself. One of themethods that he uses to maintain duck feedintake, a key parameter of productivity, is to offerthe feed as a moist mash frequently during theday. At the hottest time of the year, he also feedsduring the night when temperatures are lower.Leftovers from each feeding, which quicklybecome unappetizing, are washed into the pondfor fish. Additionally he uses pig manurepurchased from a neighbouring farm and varioussupplementary feeds if available.

Surin’s use of duck manure in Nakon Pathum, Thailand

BOX 5.M

� Type of animal (size, growth rate, feed andgrowth efficiency, sex).

� Housing (open, closed).

� Manure used fresh or collected, stored andtransported (CST).

� Nature of bedding materials (bulk density,particle size, moisture retention capacity,compressibility, penetrability, hygroscopicity,biodegradability).

� Quantity of bedding or cleaning materials persurface unit (nutrient dilution, microorganismactivity)

� Inclusion or exclusion of urine.

� Nature of ingredients in feed (digestibility,nutrient density and composition).

� Feeding method and presentation; ad libitumor restricted; as a dry mash, wet mash, pel-letised for concentrate diets or whole, shred-ded for leafy diets.

� Litter management (regular/irregular removal).

� Type of waste storage (aerobic, anaerobic,exposure to temperature, rain, wind).

Source: Modified after FAO (1980)

Factors affecting characteristics of livestock waste and its use for aquaculture

BOX 5.N


� What is the demand for and value of the live-stock and fish species to be produced?

� What are the production cycles of the fish andlivestock species? How does waste produc-tion by the livestock vary with time?

� Are there any variations in ambient tempera-ture throughout the year?

� What is the feeding niche of the species to becultured?

� What is the sensitivity of the desired speciesto dissolved oxygen level?

� What is the value of livestock waste1 com-pared to farm-gate prices of fish, inorganicfertilizer and supplementary feed?

� Has the waste been stored or mixed with

other materials. If so what effect has this hadon nutrient concentration and availability?

� Could the wastes have become contaminatedduring production, storage or transfer to thepond with substances harmful to fish or natu-ral food webs?

� What proportion of the wastes (solid and liq-uid) produced are available for collection/usein fish culture?

� What is the C:N ratio of the waste to be used?Is it in the right range to allow adequate waterquality to be maintained at the loading used?

� Are other nutrient inputs (feed, fertilizers) tobe used in the pond? If so, what is the totalexpected dry matter loading?

Questions to ask during the design of livestock-fish systems

BOX 5.O

1 Opportunity cost for use elsewhere on the farm (field crops, horticulture), sold off or used for biogas production.

ABOVE

Ducks confined over fish ponds may aerate the waterthrough their swimming and feeding behaviour

RIGHT

Collecting urine and washing water from pigs fattenedon concrete-floored pens

CHAPTER 6 • PUBLIC HEALTH AND LIVESTOCK-FISH 85

Public health and livestock-fish

6

The public health implications of livestock-fish integration are

investigated in this chapter. Many of these are as important for specialized, stand-

alone livestock and fish production as for integrated systems. Historical associations

between human health and livestock production are compared to modern threats and

how a large range of inputs to livestock, fish and wider food production systems may

impact directly or indirectly on public health. Identifying the hazards and assessing

the risks of pathogens including bacteria and viruses and parasites, are considered,

and the involvement of integrated farming in influenza pandemics is discussed.

The importance of both chemical and biologicalhazards is raised. The current debate about anti-microbial resistance is interpreted from thestandpoint of extra risk due to integration.Relative risks from bioaccumulation and toxicalgal blooms are discussed.

General considerationsPublic health issues can be considered as thoseof direct importance to both producers andconsumers of fish and include broader issues of

food production, processing and deliverysystems. Linkages have been made between fishor livestock production and health in terms ofcommunicable diseases, non-communicabledisease, malnutrition and injury (Birley and Lock,1998). Clearly, the improved availability of low-cost fish and livestock products for people’snutrition needs to be placed in perspective withlikely risks.

Threats to public health from both livestockand aquaculture are diverse. Recently, livestockand fish have been implicated in the irregularoccurrence of influenza pandemics; the globalimpacts on public health of promoting livestockand fish integration are huge if these claims are

6.1

substantiated. Certainly throughout history,infectious diseases have largely entered humanpopulations through animals (Morse, 1990). It hasbeen known for some time, that commonpathogens of warm-blooded animals do notgenerally cause disease in fish (Guelin, 1962 citedby Buras, 1990), but the role of cultured fish in thepossible transfer of pathogens between livestockand humans is important, particularly in lessdeveloped countries.

Producers and consumers in developedcountries are not immune, however, as theincreasing number of food scares indicates andthe global food trade continues to expand. Boththe resurgence of ‘old’ risks, such as the recentoutbreaks of anthrax in Australia and Thailand,and newly identified problems such as BSE in theUK show the interconnection between the healthof humans and their food. The recently identifiedproblem of Streptococcus iniae in tilapia in NorthAmerica also raises the spectre of food hygienebecoming a major political issue, complicatingthe promotion of new aquaculture species bynew producers.

Livestock and fish are involved in bothpassive and active transfer of a range of parasitesand diseases to humans, broadening the need forrisk assessment. The role of fish and warm-blooded livestock as intermediate hosts for arange of human parasites and control strategiesare well known. However, the increasing use of arange of technologies, chemicals and feedingredients in both livestock and fish productionposes a relatively new set of risks. Products suchas anti-microbials, pesticides and a range ofchemotheropeutants are often used with littleidea of either indirect or long-term risks.Prophylactic use of antibiotics and growthpromoters in intensive fish feeds rival their use inthe livestock industry. Similar problems, in termsof public health and consumer resistance, havearisen with legislation governing the use of thesecompounds in different countries threateninginternational trade. The development ofgenetically modified organisms, either as feeds oflivestock and fish, or the animals themselves hasbeen raised as both a moral and public healthissue.

A holistic, balanced assessment of risksinvolved with integrated livestock-fishproduction needs to consider the alternative andmore specialized, separate intensive systems. Anexample is the impact of livestock and fishculture on water quality as independent orintegrated activities. Pollution of surface andground water, with direct negative impacts onhealth may be avoided if wastes are recycledthrough integrated aquaculture with little to noimpacts. The pooling of water has often beenrelated to the spread of insect-vector bornediseases but use of water for aquaculture mayreduce this risk. Unmanaged water bodies inrural or peri-urban areas are more likely toharbour suitable micro-habitats for hosts’ peststhan ponds stocked and managed for fish culture.Adoption of livestock wastes for use in fishculture may already have made importantcontributions to improving health and hygiene. InTaiwan, economic growth with improvedsanitation and increasing livestock productionhave led to replacement of human waste with pigand poultry manure as fertilizers in fish cultureover the last few decades.

Risk analysis, in which hazards are identifiedand their relevance and control methodsdetermined, is a logical approach to assessingthe implications of integrating livestock and fishproduction on public health. An attempt is madeto identify the hazards associated with thevarious practices constituting integratedlivestock-fish and the risks associated with them.

6.1.1 PATHOGENSPathogens can affect human health through bothactive and passive contact. There are potentialrisks from handling livestock and their feeds,their production and slaughter house wastes asoccur in stand-alone livestock farming. Inaddition there is a need to consider hazardsassociated with transfer and use of wastes for fishculture, in management, harvest and marketingof fish, and in addition, potential risks involvedwith preparing and consuming waste-fed fish.

Guidelines exist for the use of wastewater infish culture (Mara and Cairncross, 1989) but areconsidered to be too conservative and overly



restrictive. What is important is not the presenceof pathogens in the farming environment buttheir ability to actually cause human disease.Guidelines should be based on epidemiology andnot solely on presence of micro-organisms(Blumenthal et al., 1991; Blumenthal et al., 1996).

An understanding of the main risk factors andhow to reduce them is therefore essential fordeveloping best management practice.Moreover, in order to obtain a holistic view of risk,any comparison of public health and aquacultureproduce derived from livestock waste-fedsystems should be compared to those from otherproduction systems. On a broader level, the risksassociated with disposal of untreated livestockwaste in fish ponds should be compared withalternative uses that may present greater risks topublic health in developing countries.Fundamentally a fish pond is a treatment systemfor pathogens present in organic wastes; largediurnal variations in temperature, pH anddissolved oxygen in shallow tropical fish ponds

tend to cause rapid attenuation of pathogens(Somnasang et al., 1990) (Figure 22).

6.1.2 BACTERIA AND VIRUSES

Livestock faecal wastes used as inputs into fishculture contain varying quantities of bacteria andviruses that depend on the health status of thestock and the methodology used for collection,storage and use.

Identifying hazards, assessing risksAll livestock faecal wastes must be assumed tocontain pathogens. Most disease is believed tobe transferred via faeces at slaughter. However,there is variation in the risk to human healthbased on livestock type, diet and theirmanagement. Human disease caused by manypathogens carried by livestock is difficult todiagnose. Typically, little is known about thetransferability of such pathogens to humans viafish.

Rates of faecal coliform (grey-green) and bacteriophage (blue) die-off in septage-loaded fishponds

FIGURE 22

MPN

Ind

ex/1

00 m

l

0 10 20 30 40 50

Soure: Edwards et al. (1984)

10000

1000

100

10

1

Time (hours)

Faecal coliform Bacteriophage

It should be assumed that all water used inaquaculture is potentially contaminated withpathogens, whether or not livestock wastes areused. Studies on warmwater fishponds at AITshowed that faecal coliforms, Salmonella andbacteriophage (used as an indicator of viruses)were sometimes present before input of wastes,suggesting that surface water is oftencontaminated (Edwards et al., 1983; AIT, 1986).Microbial levels increased with loading level forbuffalo manure added to the ponds daily, but notfor the wastes from egg-laying ducks raised overthe pond. In both cases, the concentration of thedifferent microorganisms increased in the waterduring the early part of the experiment beforefalling to a constant level thereafter.

The original concentrations of micro-organisms in the manure from concentrate-fedducks were much higher than in the manure ofbuffalo fed a poor quality diet but phytoplanktondensities were also far higher in duck manure-fedponds.

Whilst the levels of micro-organism in manureor pond water are important in understandingrisks to the producer, the level of pathogenscontained in the fish at harvest is of keyimportance in determining risk to thosepreparing and consuming the fish. Levels ofmicroorganisms found in the digestive tract offish are much higher than in the water illustratinga likely route to infection is via contamination ofhands and surfaces during preparation andcooking of fish. Buras (1990) developed theconcept of threshold concentration, defined asthe total number of bacteria in the fish frominspection of blood, kidney, liver, spleen, bile anddigestive tract that causes appearance in themuscle. This was developed after exposingvarious species of fish to different levels of micro-organism in the water and then determining thelevels present in various parts of the fish. Above acritical level, the immune system of the fishcannot cope with bacteria levels in the water,leading to their presence in various organs and,finally, muscle. Buras (1990) found that aggregatelevels of total bacteria present of between 1.0-2.0x 104 (Standard Plate Count, SPC) to be thethreshold concentration for common carp.

The concentration of bacteria in water that isrequired to reach these threshold values (criticalconcentration) varies between 1.0 and 5.0 x104/ml, which would require loadings far inexcess of that required for optimal fish growth.

At loading rates of manure investigated in theAIT trials which maintained good water qualityand led to optimal fish yields, the thresholdconcentrations were clearly not exceeded as theindicator micro-organisms were rarely found inorgans and were never found in muscle.Salmonella are commonly found in surface watersin nature, with contamination from wild birds alikely source. However, conditions are such inwaste-fed ponds that even heavier microbialloads from introduction of livestock manure arerapidly attenuated. Salmonella has also beenfound in shrimp pond sediment and shrimpthroughout Southeast Asia however, and thecause attributed to the use of large amounts offresh chicken manure and supplementary feeds(Reilly and Twiddy, 1992).

In contrast to bacteria, indicators forpathogenic viruses, such as bacteriophage give ameasure of faecal contamination rather than thepresence of pathogens. It is thought that entericviruses are also rapidly attenuated in waste-fedponds but their low infective dose suggest thatserious attention be given to their persistence infish ponds.

Reducing risksRisks of passive transfer of pathogens throughhandling of live fish during production, harvestand processing can be reduced if physicalexposure is minimized through use ofappropriate clothing, especially gloves. Attentionto minimise the risk of cross-contaminationduring processing should be avoided, as thedigestive tract is the major source of pathogens.Depuration, the holding of fish in clean waterwithout feeding, facilitates this task by reducingthe amount of digestive tract contents.

Consumption of raw, certain types ofprocessed, or undercooked fish should beavoided. Removal of visera and major organs, inaddition to the digestive tract, prior to marketing‘whole fish’ would also reduce risk.


Pre-treatment or processing of livestockwaste prior to its use as a fishpond fertilizer orfeed ingredient also reduces risks associatedwith transfer of pathogens. A comprehensivestudy of shrimp farms in Southern Thailand foundno evidence of Salmonella (Dalsgaard et al., 1995).A critical factor for the survival of Salmonellaappears to be adequate moisture. In asubsequent analysis, Salmonella was not found inchicken manure samples used in shrimp farms,as they tended to be sun-dried or dry pelletized(Dalsgaard and Olsen, 1995).

Depuration may not always be an effectivemethod to remove micro-organisms from fish.Buras (1990) found that when common carp wascultured in heavily polluted water, depuration inclean water for a six week period was ineffectivebecause the micro-organisms had alreadyentered the muscle tissue. The process was moreeffective with tilapia raised in optimal growthconditions in wastewater-fed ponds as theycontained initially lower concentrations ofbacteria, with none present in organs or muscle.

Streptococcus sp. infections of fish are arelatively newly identified threat to humans.Increasingly found in cultured tilapias, S. iniaeand other Streptococci that infect fish may alsoinfect humans. Infections have been contractedwhen people market live fish, or consumers arecut or spined during handling or preparation ofthe fish. The disease appears most prevalent inintensive tilapia production systems, in whichwater quality is marginal and/or there isenvironmental stress or trauma to the fish(Plumb, 1997). It has not yet been associated withfish from integrated culture systems.

6.1.3 PARASITESA variety of parasites (Trematodes, Nematodes,Cestodes) may be transfered through livestockwaste to aquatic plants and animals (fish,amphibia, molluscs or aquatic vegetables) andthen back to humans. A list of species known tobe carried by fish that affect humans is given inTable 6.1.

An understanding of current systems and thepotential reduction or increase in risk throughintegration is required. The exposure of livestock

to parasites, through foraging on human faeces isoften a critical part of the life cycle in lesserdeveloped countries lacking adequate sanitationbut if animals are penned, risks are minimal. Therisks of promoting integration of pigs and fishamong groups in which pigs are allowed to forageon human waste may, in contrast, be important.(Box 6.B)

Certain feeding practices may appear toincrease the risks of infection of livestockintegrated with fish production. Water plants thatcan be harvested opportunistically in wastewater drains or raised purposefully in watercontaminated with human faecal matter forlivestock feed are often accompanied by attached


� Good husbandry of the livestock, an ade-quate level of nutrition, hygienic accommo-dation and control of scavenging on humanwaste.

� Storage and/or composting of wastesreduces pathogens and parasites.

� Water quality suitable for optimal growth offish contains bacteria below the critical con-centration that lead to infection of fishorgans and muscle.

� Fish digestive tracts typically contain highlevels of bacteria.

� Although depuration is not effective whenbacteria occur in fish muscle, holding fishfor a short time after harvest effectivelyreduces bacteria in the digestive tract.

� Contamination of hands and surfaces duringcleaning and evisceration of fish is a com-mon route of pathogen infection throughcross-contamination of other food.

� Adequate cooking of fish ensures fish is safefor human consumption; fish eaten raw,undercooked, or improperly processed orpreserved increases risk.

Key points to reducing publichealth risks from apthogens inlivestock-fish systems

BOX 6.A


molluscs and other invertebrates which arecommonly intermediate hosts of importantparasites. Increased rates of infection are unlikelyvia this route, however, as livestock are normallyinfected by a different stage of the parasite foundin the faeces of humans. The integration ofbackyard pigs raised partly on uncooked waterplants was implicated in the former widespreadoccurrence of Fasciolopsis buski in CentralThailand however. In some cases household petscan be reservoir hosts (e.g. Clonorchis andOpisthorchis).

Pigs are the most economically and sociallyimportant livestock raised in Hmongcommunities in upland Lao PDR. These peopleare an ethnic minority with little access to themarket, educational or health resources living inone of the ten poorest countries in the World.The use of pig manure to fertilize ponds fromovernight confinement of the pigs is becomingmore prevalent, highlighting issues relating tosafety and sustainability. A multidisciplinaryapproach to ensuring success and safety of thedeveloping systems is required. Penning thelivestock without consideration that the pig dietnow lacks certain nutrients can result in failureof the system and a return to traditionalpractice. However, if significant advantages areperceived through reuse of the pig waste in fishculture, this should consolidate improved andmore sanitary approaches to pig production.Development agencies should focus oneducating pig producers on how to maintaintheir animals free of parasites e.g. Fasciolopsisbuski, Clonorchis sinensis and optimize the useof wastes. Consumers should also be targetedto improve understanding of hygienicpreparation and consumption of both pork andfish.

Source: Modified from Oparaocha (1997)

Safety issues as aquaculture stimulates changes in householdpig production in Lao PDR

BOX 6.B

Main types of parasites. Source: Modified from

TABLE 6.1

Species Reservoir hosts

Trematodiases Humans, pigs, cats, dogs and ratsClonorchis sinensis(Chinese liver fluke)

Trematodiases Humans and catsOpisthorchis viverrini and O. felineus (cat liver flukes)

Trematodiases Humans and various mammalsParagonimiasis

Intestinal Trematodiases Humanse.g. Heterophyes,Metagonimus

Nematodiases Humans, cats, dogsGnathostomaG. spinigerum

Nematodiases Migratory birds, humansCapillaria philippinensis

Cestodiases Humans, pigs, dogs Fasciolopsis buski

Fasciola hepatica Humans, sheep, cattle, (liver fluke)

Gastrodiscoides Monkeys, pigs, ratsSchistosoma spp. Some species have water buffalo,

cattle, dogs and rats


Edwards (1992) and WHO (1999)

Intermediate hosts/habitat Possible additional impacts of integration Notes

Snails especially � Feeding small, raw fish to pigs as a protein Mainly occurs in China, Parafossarulus manchouricus source could encourage re-infection Japan, Korea and Viet Nam

� Use of cooked small fish for livestock Metacercariae can persist 80 species, including 70 cyprinids are feed instead of direct consumption for weeks in dried fish reported as hosts. Many are important by humans could reduce risk and for few hours in saltedcultured species � Replacement of overhung latrines/use of or pickled products.

fresh nightsoil with livestock manure could Killed by adequate cookingreduce risk

� Increased productivity of waste-fed ponds could result in more fish eaten preserved rather than fresh, increasing risk

Intermediate host a snail, genus Bithynia � Feeding small, raw fish to pigs as a protein source Laos, Thailand, Poland, found in rice fields in endemic areas could encourage re-infection. Eastern Europe

� Use of cooked small fish for livestock feed instead No cultured cyprinids areof direct consumption by humans could reduce risk known to be important

� Less reliance of seasonal wild caught fish in as hosts-mainly wild(often preserved) most linked to infection could cyprinidsreduce overall risk

Intermediate host are snails that vary � Replacement of wild crustacea with farmed China, Ecuador, Japan,with locality and crustacea products in the diet could reduce incidence Korea, Peru, West Africa

Very common

Freshwater snails � B.gonionotus often raised in polyculture Korea, Egypt, Japan,Barbodes gonionotus infected in in waste-fed systems Philippines,ThailandNorthern Thailand with Haplorchis spp.

Low host specificity; Cyclops � Snakehead, catfish, eel and carp harbour the Thailand, Viet Nam(zooplankton),fish (snake-head), nematodes, but there have been reports linking frog, snake the disease with products of aquaculture

Small freshwater fish � No reported links with aquaculture Columbia, Egypt, Indonesia, Iran, Italy, Japan,Philippines, Korea, Spain, ThailandSpread through bird faeces

Freshwater snails, water plants � Feeding of aquatic plants to pigs may pose a risk Asia, � Confinement of pigs to allow integration with fish Eggs appear to be resistant

culture could reduce incidence to heat so thorough cooking required

Freshwater snails, water plants China

Water plants � Improved management of fish ponds may reduce Bangladesh, India, Freshwater snails incidence through reduced habitat and host Philippines, Viet Nam

� Closer integration between ducks in integrated Transmissions of eggs fish culture could control snail hosts through both faeces (S.

japonica and S. mansoni) and urine (S. haematobium)

Source: AIT (1986)


In Southeast Asia where helminth-relatedhealth issues are most important, aquaculturetypically develops from more extensive, and oftencommunity-based, aquatic resource manage-ment. Stocked and wild fish are often present inthe same systems and thus risks associated withgreater infection with Opisthorchis, which ispresent only in indigenous cyprinids (WHO,1999), could be magnified by promotingintegrated aquaculture.

Reducing risksImproved sanitation or human waste disposal is akey element in the control of parasites, as is thecontrol of pond-side vegetation that providescover for snails which are often intermediatehosts. Education and the availability of anti-helminth drugs are also prerequisites forsuccessful improvement of public health at thecommunity level.

Aquaculture may also reduce the healthimpacts of parasite diseases. Key aspects of thisare through habitat modification and hostcontrol.

Although most fish species have been foundto be relatively ineffective at biological control ofsnail intermediate hosts (McCullough, 1990),snail-eating black carp (Mylopharyngodonpiceus), and ducks can be managed to controlthem to a limited extent. The Louisiana redswamp crayfish (Proambarus clarkii) is beingused in an attempt to control freshwater snails inKenya (Hofkin et al., 1991). Abandoned or poorlymanaged fish ponds have been associated withschistosomasis in Africa (McCullough, 1990) butwell managed, productive systems in whichaquatic weeds and molluscs are removed ormanaged are probably less of a problem.

6.1.4 INSECT-VECTOR BORNE DISEASES

Poorly-managed fish ponds often becomemosquito-breeding sites (Birley and Lock, 1998).Removal of surface and emergent vegetation, as apart of intensified aquaculture, reduces shelterfor mosquito larvae. Introduction of aquaculturehas actually decreased the incidence of diseasethrough reduction of the habitats of the vectors or

intermediate hosts such as mosquitoes andsnails in Israel and China respectively.

6.1.5 INFLUENZA PANDEMICS

A major issue regarding the promotion ofintegrated livestock-fish production has been thepossible connection between such practices andthe emergence of influenza pandemics, a linkwhich has led to heated debate in both thescientific and popular literature (Scholtissek andNaylor, 1988; Edwards et al., 1988; Edwards, 1991;Skladany, 1996). It has been claimed that thefarming of pigs, poultry and fish together on thesame farm is predisposing Asia, and the world, tothe emergence of new virulent strains of influenzavirus. Human influenza viruses are similar topoultry viruses but require change before they caninfect humans, a change that can occur in pigs orbetween chickens and ducks (Li et al., 2003).Recent evidence suggests that not all human flupandemics started in Asia, nor are they related toavian viruses. The outbreak of Spanish flu, whichkilled 20 million people in 1918-19, is believed tohave started in the US, and recent analysis showsthat the strain is unrelated to poultry and closer toa pig virus (Taubenberger et al., 1997).

The known possible transfer of such virusesfrom poultry to pigs, which act as ‘mixing vessels’for the virus to undergo ‘antigenic shift’ is notquestioned by aquaculturists, but rather the roleof aquaculture in the process. Modern, integratedsystems in which both poultry and pigs are raisedtogether on the same farm with fish, are rare forfundamental economic reasons, whereastraditional farming of poultry and pigs together onfarms without fish is common throughout thedeveloping world, and especially in China. Hometo many of the world’s poultry and pigs, China isalso the putative origin of new strains of influenza.Where markets and production systems areintermediate between backyard and commercial,many ‘hybrid’ systems do exist however. A recentstudy in the environs of Ho Chi Minh City foundthat although pig/fish, chicken/fish and duck/fishsystems comprised over 70 percent of livestock-fish systems, over 20 percent of farms withlivestock and fish raised both poultry and pigstogether (Nguyen and Trinh, 1998).


Chemical hazards and associated risksA major issue is how integrating livestock andfish together can reduce the level of chemicalhazards and associated risks compared to stand-alone enterprises. We first explain the range ofchemical hazards with a tabulated assessment oftheir importance to both integrated and non-integrated aquaculture compared to, whereappropriate, reference to wild stocks (Table 6.2).Generally, hazards associated with intensiveaquaculture, particularly of carnivorous fish, arelikely to be greater than less intensive culture ofherbivorous and omnivorous species because ofthe greater likelihood of bioaccumulation andexposure through the higher levels of waterexchange required. Wild fish in unmanagedaquatic systems may suffer more from the effectsof chemicals than cultured stocks as aquatichabitats often serve to drain effluents and run-offfrom agriculture, and complex natural ecologiesare more likely to be disturbed than closelymonitored culture systems. Chemicals mayaccumulate more in slow-growing, carnivorousspecies than well-fed, short-lived farmed fish.

Exposure to chemicals can be accidental orpurposeful. Contamination of the surroundingenvironment, water or feed source for fish orlivestock integrated with fish can be either acuteor chronic in nature. Chemicals are also oftenused as part of disease control, generalhusbandry or as feed additives. The tendency inintegrated systems is for the fish culturecomponent to be semi-intensive i.e. relatively lowdensities of fish feeding low in the food chain andthese are less likely to require treatment fordisease, intensive disinfection or specialized feedadditives. Clearly, chemical hazards inherent inlivestock production have greater potential foraffecting fish in such systems than vice versa.

Range of chemical hazardsChemical hazards may arise from the use ofagrochemicals, chemotheropeutants, metals, feedingredients and organic pollutants. Agrochemicalsi.e. chemical fertilizers, water treatmentcompounds, pesticides and disinfectants arewidely used in both commercial and smallholderfood production. Chemotherapeutants include arange of compounds used to control the impact ofdisease on both livestock and fish i.e.antimicrobials, parasiticides and hormones. Theissue of bacterial resistance induced throughprophylactic use of antimicrobials and drug

6.2

ABOVE

Farms which raise two types of livestock together on thesame farm with fish are rare. This farm is using the roofarea of a pig unit to shade caged egg chickens. Casualmixing of pigs and poultry is more likely in traditional systems, irrespective of whether fish are cultured

RIGHT

Village chickens scavenging for waste feed within intensive battery egg units may spread disease


residues that risk human health are of key interest.Exposure to metals, in addition to that fromchronic or acute pollution of aquatic systems, mayoccur due to their use as anti-foulants andmolluscides or through their inclusion as growthpromoters in livestock diets. Other feedingredients have come under recent scrutiny and,especially as use of manures as fishponds inputsmay increase the pathways through which thesecompounds can enter the human diet, should beconsidered. Aquatic systems are particularlysensitive to organic pollution. In this regardexposure to chlorinated hydrocarbons that arepersistent and can bioaccumulate, is of specialsignificance (WHO, 1999).

Integrated management of livestock wasteand fish production ideally leads to good practicethat reduces the necessity for use of chemicals tocontrol pests and maintain optimal conditions.The frequent collection and use of manure for fishculture can reduce problems associated with itsaccumulation and storage such as the spread offlying insect-born diseases or ammonia-relatedrespiratory problems. Moreover, many farmershave found that siting of livestock pens overponds improves the environment for the livestockthrough evaporative cooling; this is particularlyimportant in the tropics where more expensivemethods of controlling heat losses areuneconomic and heat stress is a major factorpredisposing livestock to disease. In the sub-tropics prevention of wind-chill is often requiredduring seasonally cooler weather.

Inland carp farms as examples of semi-intensive aquaculture often integrated withlivestock production were found to havenegligible use of antimicrobials (ICLARM, 1996;NACA, 1997). This is undoubtedly related to theexcellent water quality and nutrition that can bemaintained in semi-intensive systems, reducingthe need for such inputs. The only chemicalslikely to be used directly in greater quantities insemi-intensive than intensive aquaculture arechemical fertilizers, for which livestock wasteoften substitutes in integrated systems.However, since fish culture is typically integratedwith intensive feedlot-based production, thetransfer and hazards associated with chemicalspresent in the resultant wastes are an issue.

Antimicrobial resistanceThe potential problem of bacterial strainsbecoming resistant to the use of antimicrobialshas been raised, although rarely objectivelyassessed (WHO, 1999). There are two major risksof resistant strains being a hazard to humanhealth: those associated with transmission ofresistant strains from aquaculture to humans;and the possibility of non-pathogenic bacteriacontaining antimicrobial resistance genes beingtransferred to human pathogens. In the tropics,fish pathogens such Aeromonas hydophila andEdwardsiella spp. can cause human disease andthe first risk, although not quantified, does exist.The second does have a potential link,particularly if drinking water is obtained from fishponds. The risk was judged to be small asantimicrobial compounds are used to a verylimited extent directly in freshwater aquaculture(WHO, 1999). However, this risk assessmentdisregards the large quantities of anti-microbialsused both prophylatically and for diseasetreatment mixed with feed and water in feedlotlivestock. Considerable quantities of feed anddrinking water are known to be lost directly to thefish system, and the risk of survival and transferof resistant bacteria within tropical fish ponds isa recent focus of enquiry. Although farmingintegrated fish has been found to increaseprevalence of antimicrobial resistant bacteria infish ponds and guts (Petersen, 2003), this is likelyto be greatly outweighed by other causes ofantibiotic abuse within livestock production perse and in human medicine (A. Dalsgaard, pers.comm.).

BioaccumulationThe risk of accumulation of both drug residuesand heavy metals in tissues of fish raised in semi-intensive systems is probably lower than fishraised intensively because direct use of feedadditives and chemotheropeutants is verylimited (WHO, 1999). Moreover, as waterexchange is minimal in such systems, thelikelihood of acute impacts from pollutionincidences is also likely to be lower than forintensive systems using more water. Organicpollutants, however, may potentially concentratein rainfed fish ponds within watersheds receiving


run-off from agricultural land in whichinsecticides are used, but limited data areavailable. It is expected, however, that pondsediments, especially in fertilized ponds, act as asink for these compounds, reducing losses to thewider environment with consequent effects onnatural systems.

As toxins concentrate through the food chainand their growth is relatively slower, wild,carnivorous fish are more likely to accumulatemetals and organic pollutants than fast-growing,cultured fish.

Biological hazardsMicroalgae and detrital bacteria that serve asfood for cultured finfish and crustaceans producemost toxic compounds affecting aquaculture.The toxins produced by blue-green algae(cyanobacteria), microcystins, are particularlypotent and widespread in fertilized freshwaters(Codd, 1995; Codd et al., 1999). The optimalenvironments for raising filter feeding Nile tilapiaare known to be highly fertile water dominated bycyanobacteria such as Microcystis aeruginosa

(Colman and Edwards, 1987). The evidencesuggests that not all strains of cyanobacteria are toxic and that filter feeding fish avoidingesting toxic cells (Beveridge et al., 1993;Keshavanath et al., 1994). When fish losses occur,often at the end of plankton blooms, it is unclearif mortalities are related to the depleted levels ofDO levels that occur or the toxic effects of freemicrocystins released into the water. However,accumulation of microcystins has beendemonstrated in the livers of freshwater fishunder such conditions (Codd and Bell, 1995). Ithas been concluded that the risk to human healththrough eating farmed finfish and crustaceacontaining these toxins is very small (WHO,1999).

Indirect effects of aquaculture, especially insystems based on controlled fertilization, shouldconsider the known effects of microcystins onlivestock. The potential for contamination oflivestock and human drinking water throughnearby aquaculture does not appear to have beenresearched. The relative value of surface water asa potable source compared to alternative sources,and the potential contamination of ground waterthrough seepage of microcystin-rich pond water,need to be better understood.

6.3

� Reduction in risks from parasites in livestock-fish systems needs to consider current feed-ing and management practice and minimizingcontact with intermediate hosts.

� Improved sanitation, anti-helminth drugs andbiological control are also important.

� Well-managed productive ponds in whichaquatic weeds and molluscs are controlled,reduce risk of parasite transfer and insect vec-tor-borne disease.

� There is no evidence that livestock-fish inte-gration has been linked to the incidence ofinfluenza pandemics. But multi-species live-stock production, especially pigs and poultry

should be avoided in specialized units or inte-grated with aquaculture.

� Livestock-fish integration probably reducesthe overall risk of contamination with chemi-cals compared to production of intensive,stand-alone fish production or fish capturedfrom the wild.

� The risks to human health through micro-cystins produced by blue-green algae in live-stock waste-fed ponds are very small.Eutrophication of any surface water, throughuse of fertilization, or occurring as a result offeeding fish intensively, need to consider themultipurpose use of water.

Key points to reducing public health risk due to parasites and other biological and biochemical agents

BOX 6.C


Chemical hazards and associated risks to fish production

Category Intensive Semi-intensiveNon-integrated

Agrochemicals Little used May be most important type of nutrient input Chemical fertilizers e.g. single compound Unknown impacts of nitrogen leaching to or compound fertilizers ground water used for drinking water source

Agrochemicals Little risk Little riskWater treatment compounds e.g. lime compounds (limestone, lime and hydrated lime) oxidising agents (potassium permanganate, calcium hypochorite), flocculants (alum, zeolite, gypsum) lime,hydrated lime, Osmoregulators (salt, gypsum)

Agrochemicals Used in channel Polyculture of filter feeding fish Pesticides-mainly used in ponds catfish ponds to obviates the need for their useAlgicides e.g. copper, triazine herbicides) control microplankton

Piscicides mainly used to control competitive or little effect Commonly used in pond culturepredatory wild fish e.g. teaseed cake, mahua oil cake, rotenone, urea, lime, phostoxin

Insecticides mainly used to control competitive or Used most intensivelypredatory insects and zooplankton* in intensive nursery

pond production

Agrochemicals Disinfectants Used most in intensive e.g. benzalkonium chloride, polyvidone iodine, systems for disinfection gluataledehyde. Formalin, hypochlorite of equipment and

holding units

Chemotherapeutants Controlled use in some Very little used (<5 percent)Antimicrobial agents countries; Few controlsAntibiotics eg oxytretracycline, oxolinic acid, amoxicillin, and commonly used in co-triamazine, flumequine intensive fin fish and

shrimp production in Asia

Chemotherapeutants Particularly important in Not widely used in pond-based aquaculture, although Parasiticides cage-based systems e.g.organophosphates where fish are raised at

high density

Chemotherapeutants Hormones used to induce spawning but very small quantities which can beOthers e.g. hormones control, especially in the tilapias, and large hatcheries may produce relatively

juvenile stage and rapid excretion rates suggest there is no risk. Impacts onnegligible as little water exchange required.

MetalsAntifoulants and molluscicides Particularly important in Used in pond preparation, often with lime which e.g. copper sulphate intensive systems prevents high concentration in water. Bioaccumulation

not a problem in fish but could be in shellfishTributyltin Salmon have been Used in rice production to control Golden Apple Snails

shown to accumulate with negative health impact on livestock and humans(Halwart, 1994)

TABLE 6.2


Wild stocks NotesIntegrated

If animal manures are not limiting, Use in agriculture may impact on unmanaged unlikely to be important aquatic systems affecting biodiversity,

sensitivity to toxic algal blooms

Little risk Little risk Handling hydrated lime

Polyculture of filter feeding fish obviates the need for their use

Commonly used in pond culture

Organophosphate and pyrethroid insecticidesused in livestock production pose a threat to fish if washed into ponds with wastes

Widely used to disinfect livestock units,may contaminate wastes and/or bedisposed of in ponds.Limited database on effects

Very little used in fish but present in waste feed, and as residues of digestion (faeces) and metabolism (urine) in livestock waste

can be used for ectoparasites Principle health hazard to people working with the products

rapidly excreted. Steroids used for sex large quantities. But only used at the receiving water are also likely to be

Unlikely to present a serious risk undernormal conditions but available data base isinsufficient to permit a definitive statement.Some persistent insecticides (organo-chlorines) are known to be used. Use byyoung people without proper informationor protection poses a real threat to theirsafety. Natural products may be more toxicthan synthetics.

Handling of all hormones should be carriedout using normal precautions and should belimited to facilites where this can be ensured

(Continued on page 98)


Chemical hazards and associated risks to fish production

Category Intensive Semi-intensiveNon-integrated

Metals Bioaccumulation Lower risk of bioaccumulation in herbivorous/Pollutants from acute or chronic pollution suggests that intensively omnivorous fish. Fast growing fish harvested young

raised fish fed high also likely to have lower levels.levels of fishmeal are High pH, increased hardness and high content of likely to have higher soluble and suspended organic compounds that are levels of methyl mercury typical of pond aquaculture, reduce mercury uptake.

Unknown risk of chromium contamination of fish ponds in Calcutta.

Feed Ingredients Large numbers of More likely to use locally available ingredients. Dependent on a series of steps from growing and additives, often used in Maybe fresher,or stored under poorer conditions harvest of feed ingredients to ingestion by the animal small quantities, used in and contaminated by mycotoxinsIncludes additives and contaminants complete formulated

feeds.Fish oils particularly likely to have high levels of chlorinated hydrocarbons-mainly used in intensive mariculture.

Organic pollutants Contamination of Fish raised in wastewater containing industrial chemicals Acute and chronic pollution feedstuffs, e.g. in 1994 chlorinated pesticides. Such fish may become unmarket- e.g. chlorinated insecticides one third of channel high health risks occurand their degradation products PCBs catfish contained high High levels of dioxin and PCBs in livestock feed ingred- Dioxins and furans levels of dioxin Edwards, 1999)

Fish raised with a high fat content are likely to concen-

TABLE 6.2 (continued from page 96)


Wild stocks NotesIntegrated

Slow growing, carnivorous fish likely to have highest levels

Risks associated with livestock diets since contaminants may be present in waste feed, and as residues of digestion (faeces) andmetabolism (urine) in livestock waste

usually show only low tissue levels of Speculation about contamination of With the exception of chlorinated able through off-flavours before freshwater fish in Southeast Asia due to hydrocarbons-most industrial chemicals

widespread use of Agent Orange as a and agrochemicals are degraded. ients are occurring regularly (Little and defoliant. (Schecter et al., 2001) Global distribution of dioxin; tend to

accumulate in colder climes and reduce trate these compounds. relative concentration in tropical waters

Source: Modified from WHO (1999)


A major issue is whether algal bloomproblems, and health impacts on people, aremore or less likely to occur in fish culture systemsintegrated with livestock waste than eitherintensive, stand alone aquaculture or infertileextensive systems. Intensive fish culture basedon complete feeds can also cause rapid andsustained eutrophication. Clearly, promotion ofwaste-fed aquaculture requires consideration ofthe overall water needs of households.

SummaryThe use of human and livestock waste in semi-intensive fish culture, subject to certainsafeguards, can generally be considered positivein any holistic assessment of risk (Edwards,1993). Semi-intensive systems fertilized withinthe carrying capacity of the system are healthyenvironments for fish. The fish production unitcan act to ‘treat’ wastes that themselves maycontain pathogens, provided certainprecautionary steps are observed. Moreover, non-integrated intensive livestock and fishproduction carries its own risks to public health,which should be considered in any balancedcomparison.

6.5

CHAPTER 7 • SOCIAL AND ECONOMIC CONSIDERATIONS 101

Social and EconomicConsiderations

7

Improving the quality of life for the poor in developing countries

will depend on reducing population growth, while improving nutrition and

opportunities for income generation. Demographic trends show that many more

mouths will need to be fed before human populations stabilize in most developing

countries. Increased consumption of livestock products and fish are indicators of

rising affluence. Meeting these needs without resorting to ‘disruptive technologies’

(Harrison, 1992) that together with population growth and increased individual

consumption cause negative environmental impacts, is a major challenge. The

appetite of growing urban centres for animal products can too often translate into

environmental damage and decline of traditional mixed farming (Steinfeld et al., 1997).

Both livestock and fish production can havenegative impacts but if production can beintegrated, benefits are likely to be moreequitable and ecologically benign. Benefits ofproductive integrated livestock-fish accrue toproducers, consumers and society in general. Acrop of fish, raised at little extra cost, spread risksand diversifies livestock production. Theproduction cost of the fish should be low sincelivestock waste is substituted for purchasedfeeds and/or chemical fertilizers, with potentialbenefit also to consumers. Moreover, their

integration can, through a low technologyapproach, ameliorate the negative impacts oflivestock intensification. Wastes that otherwiseadversely affect surface water supplies and thepeople dependent on them, can be treated atrelatively low cost and valuable nutrients used and retained within the farming system (Chapter 4).

Livestock-fish production has been mostlyadopted by livestock entrepreneurs, often in peri-urban areas, rather than the rural poor. Betteraccess to inputs and markets favours this group.


As developing countries become increasinglyurbanized, the role of entrepreneurs in producingcheap food for poor urban as well as rural peopleis likely to increase. A major challenge is also tobring the benefits of integration to poorer farmerscurrently not producing fish at all or raisinglivestock and fish separately with low andinefficient production.

Fish and other aquatic animals are importantboth for their intrinsic nutritional value and theirmajor role in the food security of some of thepoorest people in the region. People living inAsia’s floodplains have been particularlydependent on growing rice and catching wildfish, so-called ‘rice-fish cultures’, but are alsonow consuming increasing quantities of ‘wheatand meat’. Urbanization and increasing wealthhave stimulated these trends toward a morediversified diet. In much of Asia, however,increased purchasing power also stimulatesincreased consumption of fish, particularlycultured fish. Urban areas as diverse as Bangkokand Hanoi have seen rapid increases in thedemand for cultured fish. While fish protein as apercentage of animal protein in the diet declineswith an increase in living standards as peopleconsume more meat relative to fish, the absoluteconsumption of fish tends to rise also.

The integration of fish culture withinfarming systems could also allow increases infish consumption by people previouslyconsuming little, or for whom the culture of fishhas yet to develop as a viable alternative toexploiting wild stocks. This factor, together withpredictions of ever increasing global trade infood, suggest that exports of both livestock andcultured fish will continue to rise. In manywestern countries, fish consumption is nowgrowing much faster than consumption of meat,partly due to increased awareness of the healthbenefits of fish in the diet. Where aquaculture isviable in developing countries, promotingherbivorous fish raised on manure, rather thancarnivorous fish species fed largely on other fishshould be vigorously promoted by national andinternational organizations. This strategy hasthe best chance of meeting the needs of poorpeople, both producers and consumers. It canalso avoid negative environmental impacts

associated with specialism and separation ofaquaculture and livestock production (seeChapter 4).

The use of livestock wastes to raise fish on ahousehold level is a method for people to addvalue to the assets they already possess, whilediversification allows poor people to offset risk.Livestock production is one of the most commonmethods of saving for the rural poor. Income fromsale of livestock products can also be veryimportant. Raising livestock, often on wastes andby-products, is also common among poorerpeople in peri-urban areas striving to balance aportfolio of different activities. If further value canbe added by raising fish on livestock wastes in awater body close to the house, contributions toimproved livelihoods may occur in a variety ofways. The nutritional benefit of eating culturedfish has been a major incentive to promoteaquaculture, even among people whotraditionally consume little. Adopting fish culturemay help to develop a broader range of humanand physical capital as improved knowledge andskills gained are applied more widely.

Understanding cultural norms concerningconsumption of fish, and resource constraintsand conflicts, is essential if integrated livestock-fish culture is to be promoted effectively morewidely. The factors that drive or restrain thedevelopment of integrated farming are complex.On-farm most of these relate to constraints to thecollection and use of livestock manures (seeChapter 5) but off-farm factors often dominate.Poor availability of inputs e.g. fish seed andlivestock feeds, and markets may restrictinterest. An ‘information gap’ is clearly a majorconstraint that needs to be addressed. Culturaland social values may also support or undermineefforts to promote integrated practices, many ofwhich have their roots in earlier stages ofagricultural development.

The promotion of integrated livestock-fishculture has been adversely affected by itscomplexity and the limitations of conventionalextension approaches. A range of approachesthat are participatory at both the farmer andinstitutional level show promise for greatersuccess, providing off-farm factors remainpositive and supportive.


DemandPhysical environments, and the cultures thathave developed in them, have shaped dietaryhabits and the acceptability of certain livestockand fish. Taboo foods, be they pork amongdifferent groups in arid areas of the Middle East,South and Southeast Asia or fish to certaingroups of people in Africa and Asia may have animportant underlying basis. Clearly, thepromotion of livestock or fish production topeople who are disinclined to consume either

would be problematic. Recent examples ofcrop/livestock systems evolving in Asia can all belinked to a strong market demand for theproducts, be it the ‘white revolution’ in thePunjab where intensive dairying has developedrapidly, to an expansion of the ‘balut’ duck eggproduction in the Philippines.

The factors that stimulate growth of livestockor fish to be key parts of any particular farmingsystem are complex but clearly consumerdemand is critical. The comment that ‘whateverthe biologist may conclude about relativeefficiencies of different livestock, farmers willcontinue to produce what the consumer likeseating, as long as he is prepared to pay for it’(Spedding, 1971) reflects richer peoples’ attitudesto livestock consumption. Clearly, the majoropportunities for growth in integrated live-stock-fish lie with species that are culturallyacceptable, profitable for the producer andaffordable to the consumer. Thus, although mostAsian consumers may favour freshwatercarnivorous fish species over herbivores, theycannot be raised cost-effectively in waste-fedsystems. The production of carnivorous fishspecies on trash fish and fishmeal-based pelletssoon reaches a plateau in each society asdemand by the wealthier people has been met. Incontrast, the rise in production of fish feeding lowin the food chain continues to meet unfulfilleddemand for low-cost animal protein by themajority of the population in countries promotingaquaculture in Asia.

Experience shows that even new species canbecome popular with both producers andconsumers as their relative advantages becomeclear. Tilapia has moved from being a weed fishrarely sold in markets to economic significance inseveral Asian countries. This is mainly becauseNile tilapia, which also thrives in waste-fedsystems, has substituted for inferior species.Tilapias have come to dominate the production oftraditional carps in areas where feedlot livestockwaste is abundant and its opportunity cost lowsuch as Taiwan and Central Thailand. Thepopularity of integrating pigs and poultry withfish in these and other areas is based on theincreased demand for a traditional food, i.e.poultry and pig products, that has grown rapidly

7.1

� Improved nutrition through consumption ofcultured fish within the household, or pur-chase of food using income derived fromfish sales, can contribute to improved liveli-hoods as peoples’ health and educationimprove.

� Production of both livestock and fish diver-sifies household assets

� Entrepreneurs dominate peri-urban integrat-ed livestock-fish production, producing foodmainly for those in urban-industrial commu-nities, including the poor.

� Global trends suggest that the need for cul-tured fish and livestock will continue toincrease as purchasing power and demandfor diverse diets both increase.

� Integration with fish culture can reduce theenvironmental impacts that non-integratedlivestock production inevitably causes, andproduce high-value, low-cost food close tothe market.

� Cultural and social values can undermineattempts to promote integrated livestock-fish production.

Summary of key points relating tosocial and economic issues

BOX 7.A

with improved purchasing power. It is attractivefor modern feedlot systems that produce largeamounts of nutrient-rich waste to dispose of it innearby ponds.

Subsistence attitudesSmall-holders, who consume much of what theyproduce, have different value systems tocommercial farmers and urban consumers. Therain-fed, rice-biased agricultural cycle determinesboth supply and demand for poultry and culturedfish products in much of rural Asia (Little, 1995).Resource-poor farmers raise different livestock fora whole range of reasons, and culture of fish isequally complex. Wild and cultured fish are oftenviewed very differently. In Northeast Thailandcultured fish are highly valued for theirconvenience during the rice harvest period whenneighbours and relatives are entertained (Box7.B). This attitude partly explains the prevailingextensive management and the practice ofholding fish for prolonged periods (Chapter 8). Theview of cultured fish as a ‘convenience food’, asimilar attribute to that of home-raised poultry,which can be accessed without planning or usingcash reserves is also highly valued.

Both fish and small livestock meet a variety ofneeds, fulfilling roles defined within both‘physical’ and ‘social’ assets used in livelihoodsanalysis. Any promotion of integration oflivestock and fish must recognise the diversityand individualistic needs, rather than simplecommercial models focusing on ‘efficiency’ and‘output’. Moreover, wealth, social status andgender further complicate attitudes to, and thepractice of integrated farming.

The factors that affect production andconsumption of fish are varied and interlinked.Demographic changes point to increasingimportance of peri-urban production to meeturban demand and yet aquaculture also developsin the absence of formal markets. Informal sale,exchange and use of fish as gifts are oftenunderestimated and yet form an importantcomponent of demand that is underestimated inofficial statistics. In areas where wild fish are atraditional dietary staple, farmer aspirations mayat first focus on subsistence but can shift quite

rapidly to income generation once confidence isgained (Edwards, 1997). Natural stocks of aquaticproducts, including frogs, crabs and variousinsects were, until recently, adequate forsubsistence purposes in all but the most denselysettled rural areas of Asia. Undeveloped marketsfor these highly perishable products probablyconstrained commercialization (Little andEdwards, 1997).

In a similar manner to poultry, the socialvalues of exchange and reciprocity are moreimportant in rural areas than the cash/creditsystems which dominate urban areas. Farminghouseholds raising fish may have mixed motivesthat include reducing costs associated withharvesting dwindling wild stocks, safeguardingfood security through consumption, or sale anduse of the cash for purchase of alternative,cheaper foods.

UrbanizationMany of the factors driving the specialization oflivestock and crop production on Asian farms arerelated to the two major impacts of urbanization:the creation and growth of urban marketsrequiring consistent supplies of food; anddepopulation of rural areas that dampensdemand for food produced in traditional systems(Pingali, 1995). Rural depopulation is often linkedto improved infrastructure such as roads andcommunications; it has varying characteristicsthat have different outcomes in terms of ruraldemand. Out-migration may be either chronic orlong–term, or seasonal or short-term, in nature.Communities negatively affected suffer in termsof low and erratic purchasing power and lowinvestment in agriculture (Turongruang et al.,1994; Little, 1995).

Industrial food production favoursconcentration near urban centres because of arange of factors. Of these transport costs andmarket opportunities are of greatest importance.It is less costly to transport high-energy, livestockfeed from distant production sites thanperishable livestock products; and thisencourages production, slaughter and meatprocessing facilities in peri-urban areas (de Haanet al., 1997).



The trends of intensification and specializationof livestock production have been challenged onecological and social grounds. Although intensifi-cation should ultimately improve the quantityand variety of livestock products available tourban consumers, the proportion of urban poor

will grow as opportunities for livelihoods dwindlein rural areas. Increase in farm-unit size anddecline in the total number of farms will increasethe flow of the rural poor to urban areas,intensifying urban and rural social problems.These views have popularized the rationale for

� Marketing of a proportion of the poultry andfish raised by small-holders is typical amongfarmers in Northeast Thailand. Although suchsales constitute only a marginal source ofannual income, poultry are valued for theirrole as liquid assets as they are mainly soldwhen cash expenditure of the household ishigh. The social role of poultry and both wildand cultured fish is particularly clear duringthe rice harvest season when meat consump-tion is high as friends and relatives are enter-tained. Cultured fish and poultry are a con-venient and available high-value food used atthis time.

� More than 50 percent of households in a sur-vey of six provinces of Northeast Thailandused the fish they cultured for home con-

sumption alone, but an important category ofcommercial farmer has emerged in the lastdecade in response to high demand for cul-tured fish. This minority of farmers, who aretypically resource-rich, has been very recep-tive to use of high-input inorganic fertilizationand integration with feedlot livestock.

� Households that adopt aquaculture in ruralareas of Thailand tend to consume more fishand other high quality food than non-adopters(Setboonsarng, 1997).

� Poor households in Southern Viet Nam raisedfish integrated with pigs primarily as a cashcrop; household consumption needs were metthrough capture or purchase of small wildfish.

Building social assets

BOX 7.B

Average meat consumption per household by type during the ‘feast’ period around riceharvest time of farmers adopting intensified fish culture practices in three areas of UdonThani, Northeast Thailand. Source: Little et al. (1992).

Qua

ntit

y of

mea

t (k

g)

upland mini-watershed lowland

Wild fish

Cultured fish

Village chickens

Domestic ducks

Muscovy ducks

Geese

Pork/beef

10

9

8

7

6

5

4

3

2

1

0


strengthening crop/livestock linkages throughintensification of smallholder systems (Devendraand Chantalakhana, 1992).

Accessing distant markets The development of markets, be they local, urbanor international, both stimulates and controlsefforts to promote livestock and fish production.Local adoption of appropriate fish culturetechniques can quickly lead to saturation of localmarkets, which in turn can stimulate theaccessing of distant or even internationalmarkets. Most species of cultured freshwater fishin Asia, however, are unknown in internationalmarkets. Apart from high valued carnivorousspecies that have specialized markets, mainly in

urban Asia, tilapias probably have most potentialas a global commodity.

Product quality and uniformity becomeimportant if distant markets are to be targeted.Assembling enough fish of consistent qualityfrom small-holders to meet the needs of distantmarkets is a problem, as is the likelihood of poorbacteriological quality and off-flavours.

Off-flavour problems have been closelyassociated with freshwater fish such as channelcatfish and tilapia raised in ponds or from wildstocks. Off-flavours, caused by geosmin and 2-methylisoborneol (MIB) (Dionigi et al., 1998) arenot toxic but can cause rejection of fish byconsumers, hinder marketing efforts, andreinforce product safety concerns (Dionigi et al.,1998). Organoleptic testing of tilapias raised indifferent systems indicates that waste-fed fishare no more likely to suffer off-flavours than pellet-fed fish, and may be superior in terms of fleshquality (Eves et al., 1995). The erratic quality ofTaiwan’s frozen tilapia exports have hindered thepenetration of larger markets for value-addedproducts (Box 7.C).

Nutritional benefitsFish are highly nutritious, providing animalprotein containing all 10 essential amino acids in

7.2

Taiwan is the largest producer of whole tilapiasexported to North America. The fish are raisedon livestock waste and pelleted feed but poorcontrol of product quality, and a lack ofprocessing labour, results in most of the fishbeing sold as whole frozen fish cheaply toethnic markets. Export quality tilapia, for whichthe largest potential markets exist, requiresboth significant quantities of fish large enoughfor processing (500-600g minimum) andcommitment to the management of off-flavourproblems.

Factors that support the production of export-quality tilapia include:� well managed pond-to-processing systems

that taste-tests fish just prior to harvest andrefuses unsuitable quality;

� facility for fattening in an intensive systemand depuration prior to slaughter reduceincidence of off-flavour;

� low processing costs to fillets and ready-to-cook products;

� frozen food storage capacity.

Poor quality-control hinders exportof value-added fish products

BOX 7.C

� Demographic and socio-economic changeaffects demand for fish and competing prod-ucts.

� Subsistence, exchange and use as gifts maydominate disposal of livestock and fishproducts rather than cash sale.

� Urbanization and rural depopulation greatlyaffect opportunities for, and nature of, live-stock and fish production.

� Small producers of are often disadvantagedin distant markets.

Summary of demand-related issues

BOX 7.D


relatively high concentrations. Low in cholesteroland saturated fats, they are also rich in key fattyacids, minerals and vitamins.

Inclusion of fish in diets based on traditionalhigh-carbohydrate staples typical of mostdeveloping countries is particularly valuable forvulnerable groups of people such as pregnant andnursing mothers, infants and pre-school children.This is partly because fish are a valuable sourceof polyunsaturated fatty acids (PuFAs), nowknown to be essential in development of the brainand nervous system and the proper functioningof the immune system. Recent research points tofreshwater as well as marine fish havingsignificant levels of these essential fatty acids(Steffens and Wirth, 1997).

The importance of fish in household foodsecurity in much of Asia has been frequentlystated but on a global level fish is less importantthan livestock as a source of animal protein,supplying less than 20 percent of the total fordeveloping countries. However, the averagedisguises the importance of fish in many of thesecountries, where fish meets between 40-70percent of animal protein needs (Edwards, 1997).There is clearly a huge unfulfilled need for fish tocontribute towards the livelihoods of the poor aswell as the diets of the affluent (Box 7.E).

Where natural food remains abundant,cultured livestock and fish are less important(Prapertchob, 1989; Little and Satapornvanit,1996; Edwards, 1997). In the Lao PDR small game,

both birds and mammals, and reptiles andamphibians are key parts of the diet(Srikosamatara et al., 1992). Foods derived fromwater be they insects, molluscs, crustaceans orfish contribute to a varied diet in many parts ofSoutheast Asia. Typically, wild and cultured foodis used to meet day-to-day requirements andsocial occasions. Rural households in NortheastThailand depend heavily on poultry eggs andaquatic products including fish for dailyconsumption, whereas poultry meat is mainlyreserved as a ‘feast food’ for special occasions

� In West Bengal, a rice-fish society wheremuch of the agricultural land is flooded for aproportion of the year, market surveys indi-cate that consumption of fish is far moreimportant than meat (Morrice et al., 1998).

� In two sub-districts of Bangladesh morefreshwater fish was eaten in householdswith little land than all meat combined(poultry, beef and mutton) (calculated fromAhmed et al., 1993). Fish and chicken werethe two main animal protein products pro-duced on-farm in households with ponds, ofwhich more than 80 percent was fish.

Nutritional importance of fish

BOX 7.E

LEFT

Urban markets demand large quantities of livestock products which can result in high concentrations of livestock,such as these meat ducks, being 'finished' in peri-urban areas

RIGHT

Pig pens constructed over ponds in peri-urban areas of central Thailand where land prices and labour costs are high

(Little et al., 1992). There are importantimplications for household nutrition in the use ofrice by-products for feeding livestock or fish, or inpromoting their integration. Whereas pigs arenormally marketed outside of the village, poultrymeat is used mainly for feasting, and eggs andfish are consumed regularly by everyone in thehousehold.

Gender and ageThe benefits of current livestock and fishproduction to the household and impacts of theirintegration need to be analysed from theperspective of both gender and age. Traditionalpatterns of access and control of resources withinthe household may be affected by introduction of‘new’ products such as cultured fish, especially ifit involves reallocation of resources. Participatorytools sensitive to the needs of women have beenused as part of farming system research andextension methodologies (FSR&E) to understandthe importance of gender on attitudes to intensi-fication, resource allocation and use of benefits inlivestock production (Paris, 1995). Such methodsare useful for evaluating the potential andimpacts of integrating livestock with fish culture.

DisadvantagesIntroducing fish culture can potentially increaseworkloads for certain family members and reduceoutputs of staple crops because feeds orfertilizers have been reallocated. Thereproductive roles of women may limit the timethey have available for extra productiveactivities; increasing the workload furtherthrough aquaculture could lead to overallnegative outcomes on family health.

Increased labour requirements can also resultin children spending less time at school,potentially undermining their future livelihoodprospects. Improved access to, and control ofbenefits is required for women to benefitsubstantially from new developments such asintegrating livestock and fish. Understanding therole of different household members in the

production, marketing and consumption of bothlivestock and fish often reveals an importantgender dimension. Understanding current roles,before the introduction of fish culture or itsintegration with livestock, may be important totargeting and orientating information so thatwomen do benefit and are not disadvantaged.Where aquaculture is traditional in SoutheastAsia, women in rural areas have important rolesin feeding and marketing fish but modernizationthat has increased yields has totally changedlivelihood systems (Box 7.F).

7.3


� Both gender and age in Hmong communitiesin Lao PDR affect access to, and benefitsfrom, livestock of various types. Women andchildren have primary responsibility forsmall livestock and contribute to the gener-al maintenance of larger animals, but menhave most access to resources and benefitsfrom livestock. Men were also the main pro-ponents of introducing fish culture into thefarming system (Oparaocha, 1997).

� In Than Tri district in Northern Viet Nam(Hoan, 1996) intensification of sewage-based aquaculture has had beneficialimpacts women who now spend less time onlaborious rice culture and more time market-ing fish.

� Meat duck production favoured men morethan women and children whereas the oppo-site was true for egg ducks in NortheastThailand. Men usually consumed duck meatwith alcohol, but duck eggs were a commonlunch-time food for school children. The fishproduced from the wastes was eaten byeveryone in the family however (AASP,1996).

� In female-headed households in Cambodia,which are relatively common because ofwar, aquaculture was more difficult to adoptbecause of a general labour shortage.

Access and benefits from aquaculture

BOX 7.F


Training and extensionWomen have often been overlooked in trainingand extension. Men, usually the ‘pond owner’ inboth Africa and Asia, have most contact withextension agents, who are also usually male. Menalso usually have had more access to formaleducation and generally have greater mobilityand access to information. This situation hasbeen exacerbated by poor planning andmanagement of aquaculture training, although

alternative approaches have been found effective(Box 7.G).

Harrison et al. (1994) explains the lack of pondownership by women in Africa ‘is partly due toconstraints in access to land and labour for pondconstruction and partly because in the past thetechnology has been promoted by men for men’.Assuming that knowledge will be transferredfrom the household member receiving training toothers is clearly misguided. Women also havepoorer access to credit that may be a keyconstraint to adoption of improved livestock andfish culture. Microcredit schemes may notprovide money on the right basis for supportingaquaculture but has proved highly effective forencouraging women to intensify small livestockproduction. An extension focus towards women,has been particularly successful for poultry inBangladesh and Ethiopia, and dairy goats inEthiopia (Peacock, 1996) and targeting women isan important aspect in successful adoption of fishculture in Northeast Thailand (Little andSatapornvanit, 1996).

Targeting the youngTargeting schools with information about fishculture through school fish pond projects hasbecome an essential part of most extensionstrategies in South and Southeast Asia as trainingpeople who are younger, more receptive to newideas, and literate is believed to have the greatestdevelopmental impact. The direct nutritionalbenefits of the fish produced by such students area bonus. However, retention of this expertise inrural areas is an important constraint as the youngare most prone to out-migration. In contrast,interest in aquaculture may be disproportionatelyskewed towards older family members who viewthe fish pond as a critical asset for supportingtheir subsistence needs in later life.

Food securityIn Bangladesh, small backyard ponds and ditchesare critical to supply the small wild fish used forhome consumption (Thilsted et al., 1997). Theseresources are located within the household,allowing women full responsibility and control,and attempts to introduce more productivetechniques will only be successful if women are

� Residential aquaculture training at a dis-tance from the village made participationimpossible for women in an aquaculturedevelopment project in Eastern India (M.Felsing, pers. comm).

� Training women through participatoryaction learning around their own ponds inthe village with flexible, short-term meet-ings with outside resource persons and earlyadopters has been successfully promoted bythe Vietnamese Women’s Union (Voeten,1996).

� Women and girls were less involved in small-scale, backyard aquaculture in Bangldesheven though it often occurred within thehomestead. An approach that focused ontheir needs, without excluding male familymembers, significantly increased their inter-est, knowledge and benefits from improvedaquaculture based on culturally appropriatemethods (Barman, 2000).

� A comparison of the effectiveness of videosto disseminate information about aquacul-ture found that women were more able tobenefit from this medium than men in a proj-ect in Northeast Thailand (Little andSatapornvanit, 1996).

� Generally poorer literacy levels of women inSouth Asia excludes their access to aquacul-ture information to a greater extent thanmen.

Training women in aquaculture

BOX 7.G


fully involved. Indeed, aquaculture, as a relativelynew activity, may even change intra-householdrelationships in favour of the weaker members.There may be a risk to household food security ifcommercially orientated aquaculture is promotedto men and larger, more valuable fish areproduced and marketed (Barman, 2000).

Intra-household relationshipsThe involvement of women can be eitherencouraged or constrained by the nature of thesocial norms controlling power relations withinhouseholds. It may affect attitudes towards inten-sification and integration. Inheritance practicesand divorce proceedings tend to favour men interms of retention of accumulated assets such aslivestock and fish ponds. Control of resources usedand generated by integrated aquaculture at thehousehold level is often complex and the effectivepromotion of integrated livestock-fish requiresthe control of livestock and feed resources to beunderstood. Matrilineal societies in both Africaand Asia may share certain advantages withrespect to females retaining or developing rights tofish production (Box 7.H).

A developmental focus on certain types oflivestock or fish can favour or disadvantage theindividuals most at-risk within the household. Theconsumption of certain ‘luxury’ animal and fishproducts is often subject to belief and socialcontrols (Box 7.H).

The establishment of farmer groups bygender may not be effective for extension ifaquaculture requires agreement and contribu-tions from both.

� Cash from fish sales is controlled by men,but tends to be used for household purpos-es in Zambia.

� Although fish farming is dominated by menin Malawi, production is limited in somehouseholds because women refuse permis-sion to use maize bran as a pond input.

� Pregnant or lactating women are notallowed to consume muscovy ducks (Littleet al., 1992), geese and certain types of fishin Northeast Thailand.

� Consumption of raw and pickled fish withdrink by men in Korea results in elevatedlevels of parasite infection compared towomen.

Sources: Harrison (1984); Dickson & Brooks (1997)

Intra-household relationshipsaffect production and consumption

BOX 7.H

� The traditional role of men within thehousehold normally means they are target-ed with information and support for adopt-ing integrated aquaculture. This mayexplain some of the poor success ofattempts to promote aquaculture.

� Aquaculture is a non-traditional activity inmany cases, and for this reason the oppor-tunity for women to become involved in,and benefit from, aquaculture may begreater than other activities.

� Women and children frequently haveresponsibility for management of livestock,especially small livestock.

� Attempts to involve women, children andmen in developing appropriate integratedpractices requires analysis of how informa-tion can be disseminated and used withinthe household. The needs of women balanc-ing reproductive roles, and childrens’ edu-cation need to be considered in training andextension strategies.

� Power relationships within the householdcan affect who can participate and benefitfrom integrated livestock-fish.

� Involving women and children in integratedlivestock-fish does not necessarily benefitthem in the short or longer term.

Summary of key points relating tothe role of gender in aquaculture

BOX 7.I


Resource issues7.4.1 INTRODUCTION

Closer integration between livestock and fishproduction can have impacts at the production ormicro-level, the community level and on a macro-level that affects the regional or nationaleconomy. Promoting integration where the use oflivestock waste is not traditional is often a keyissue and related broadly to the level of evolutionof the agricultural system (Chapter 2). Howresources such as land, water, nutrients andlabour are utilized to support livelihoods is relatedto their availability. Rapid development andpopulation change can drastically change the‘resource balance sheet’, requiring radicalchange in resource use.

Integrated livestock-fish can lead tocompetition for feed or waste use elsewhere inthe farming system, and such changes to thetraditional resource base, or its exploitation, can

have negative effects. A major challenge is toexplore how aquaculture, for fish is typically the‘new’ component of the food production system,can be harmoniously integrated, improving theefficiency by which resources are used.

The effects of household and communityaccess to feed resources is particularly importantas fish can compete for use of key by-products.Modern production approaches can affectavailability of feeds and waste. Theconsequences of consolidation of by-products,and livestock that consume them, are discussedin the light of impacts on the potential forintegrated livestock-fish culture. Theimplications for resource use at the macro-levelare discussed in 7.5.3.

7.4.2 MICRO-LEVEL

Using livestock waste where its useis non-traditionalAttitudes to the use of livestock waste varygreatly and are largely a function of theevolutionary stage of agriculture generally.Population pressure in particular has probablyplayed a major role in leading to culturalacceptance of use of wastes (Edwards, 1992). Iffarming practices are based on extensive, crop-dominated production with low pressure onresources, it is unlikely that people will readilyaccept manure use in fish production.

A lack of interest in using manures in pondssometimes also reflects the multipurpose natureof water bodies in which fish are stocked.Farmers usually refrain from manure use if wateris also used for drinking or other domesticpurposes. Some degree of eutrophication istolerable if alternative water for drinking isavailable and water is used only for domesticcleaning. In northern Viet Nam a variety of factorslimit the use of pig manure in fishponds, not leastthe need to use the water for washing andgrowing aquatic weeds as a feed for the pigs. Thetraditional shortage of nutrients for the staplecrop, rice, has also meant that most pig and othermanures are used on these crops. However,attempts to promote the use of livestock waste insmall-holder aquaculture, where its use had

7.4

Using inorganic fertilizers or dried chicken manureto grow back-yard vegetables. Aquaculture maycompete for the use of these scarce resources


previously been minimal, have been successfulonce the underlying constraints have beenunderstood (Box 7.J).

An analysis of the adoption and retention ofmethods to fertilize ponds disseminated amongfarmers to whom a simple buffalo manure plusurea message had been disseminated two yearsearlier found that farmers adapted theirknowledge of the benefits of fertilization to theresources available (Turongruang et al., 1994).Nearly half of the farmers continued to use

various inputs to make ‘green water’ three yearsafter they had participated in intensive farmtrials. (Table 7.1). There were no dominantreasons given by the farmers who discontinuedfertilization.

Subsequent attempts to encourage better-offfarmers, who could afford to purchase them, touse increased levels of inorganic fertilizers tosupplement limited amounts of on-farm manures,were also successful. All farmers in the trial usedhigh quality monogastric manure even if theyhad to purchase off-farm, rather than theruminant manure that they only had available on-farm (Table 7.2; Shrestha et al., 1997).

Competition for feed and wasteresourcesIntroduction of a new activity such as fish culturecan increase the strain on the household,community or regional resource base.Alternatively the fish pond, through acting as afocus for recycling and use of manure, can be astimulus to improved farming practices generally.The availability of feeds and wastes can usuallybe related to the level of agricultural intensifica-tion, market structure and costs of alternatives.

A cultural aversion to the use of manure inponds had to be overcome before fertilizationwith manures and inorganic fertilizers waspossible. � Extensive agricultural practices and low

population densities mean that few livestockare raised intensively by rice farmers andthe only manure used regularly is dried buf-falo/cattle manure in rice nursery fields andsmall amounts of poultry manure in veg-etable plots (AASP, 1996).

� ‘Green’ water, in this seasonally water shortarea, is linked in peoples’ minds to the occa-sional fetid water bodies in which a cropproduced for its fibre, kenaf, is soaked toallow the soft organic matter to decompose(‘retting’). Dead animals or pig manure aredisposed of in surface water with similarresults.

� Even farmers who understood the value ofplankton as a fish food and the need for fer-tilization, were initially hesitant until anawareness of green water was promoted in apositive light, focusing on its ‘cleanness’using a poster campaign.

� Increases of fish yields of up to 300 percentalso convinced farming households of thebenefits of fertilization and stocking largerseed (Edwards et al., 1991).

Overcoming constraints to usinglivestock waste in NortheastThailand

BOX 7.J

Adoption of livestock wastes andother inputs in aquaculture in NEThailand

Materials Average amount Households(kg. pond-1 season-1) (n=29)

Buffalo manure 890.5 4Pig manure 908.0 7Buffalo manure+urea 388.0+32.4 9Pig manure +urea 45.0+189.0 1Others +urea 900.0+9.0 1Buffalo manure+pig manure 190.0+108.0 2Buffalo manure+others 24.0+24.0 1Buffalo manure+urea+others 15.0+1.5+240.0 1Other i.e. duck manure, silkworm waste 101.0 3

Source: Turongruang et al. (1994)

TABLE 7.1


Competition for resources may be categorizedinto one of two types: Type 1, relating to feedsthat were previously available for livestock; andType 2 to manures and other byproducts oflivestock production used as fertilizers or fuel(Figure 23). Examples of the first type are theintroduction of rice bran as a supplementary feedfor fish into a village situation in which itcompetes for its use as pig and poultry feed.Another is the collection and/or cultivation ofgrass to feed to either grass carp or ruminants.

The diversion of livestock wastes for fishculture, rather than conventional crop productionas an example of Type 2, could have majorimpacts on the wider farming system,particularly in nutrient-poor environments.Sustitution of inorganic fertilizers for manures,although achievable under short-term conditions,may be unsustainable in the long term, partlybecause of changes in soil structure andchemistry. On a practical level, inorganicfertilizers may be unavailable or expensive inmany developing countries.

Overall agricultural and economic develop-ment inevitably cause changes in the relative

efficiency or kind of resource use. Development ofcrop production, processing and marketing cantotally change the availability of crop by-productsfor livestock and fish at the local level. Modernvarieties, for example, in addition to producingmore grain can also produce more by-productssuch as brans. Modern, high-yielding varieties ofcereals are generally short-stemmed, reducingthe amount of straw available for livestock feedand bedding.

Traditional uses of cereal branThe layer of fibrous bran surrounding the starchyendosperm of the region’s major cereal grains,rice, maize and wheat is a key resource forlivestock and fish production. Rice bran inparticular is critical to the production ofmonogastrics, especially pigs in Southeast Asiaand dairy animals in South Asia. Its use as asupplementary feed for fish therefore conflictswith its current use. The amount of ricebran andother by-products (principally broken rice, huskand straw) available to the household depends oncropping intensity, area, yield and post-harvestdisposal of by-products (Box 7.K). Improved

Livestock inventories and fertilizers used in an on-farm trial with farmers inUdorn Thani, Northeast Thailand

Farmer Livestock owned Livestock manure used Inorganic fertilizers (kg. pond.-1 season.-1) used (kg.ha.-1day.-1)

Ruminant chicken pig ruminant chicken pig N P

1 12 - - 1000 360 3.5 3.32 - 100 - 650 10.4 5.13 4 - 10 96 3.3 1.14 3 320 - 448 3.1 1.45 - - 7 120 2.1 1.26 - - 2 180 2.9 1.67 - - - 50 6.5 1.88 7 - - 1500 3.0 1.09 4 - - 420 0.310 1 - 3 150 200 5.9 3.911 5 - - 1150 1.8 0.112 4 72 - 2760 4.1 2.3

Source: Shrestha et al. (1997)

TABLE 7.2


FIGURE 23

Livestock

CropsFish

Manure

Inorganic fertilizers

Feed

Schema showing main possible resource flows in conventional mixed farming and thealternative use of livestock wastes in fish production

Land holding and level of intensification affectboth rice yield and availability of by-products: � in Northeast Thailand yields of around 1.7

tonnes paddy. ha-1 are normal in the single,annual rainfed crop. Riceland holdings ofaround 2 ha are the norm, producing 0.4tonnes of rice bran year-1, assuming paddycontains 12 percent rice bran. The ricemiller keeps the rice by-products as a millingfee, and raises pigs which results in concen-trations of pigs raised by fewer farmers andgenerally a much poorer efficiency in thereuse of wastes;

� in areas of the Red River Delta, NorthernViet Nam, yields of between 4-7 tonnes. ha-1

crop-1 are the norm. Two irrigated crops ofrice produce only between 0.2 and 1 tonnesof rice bran as household rice holdings are small (2 000-3 000 m2). Small holders inNorthern Viet Nam still raise pigs and retainwastes for use on the farm.

Contrasting rice land holding,rice yield and pig production

BOX 7.K

In one household, an average oftwo hours daily labour wasrequired to collect sufficientaquatic weeds to complementthe 7-10 kg rice bran and 1 kgbroken rice to fatten 4 pigs

TABLE 7.3Characteristics of pig production in three areas

CharacteristicCambodia/Lao PDR

Main feeds Rice branCooked vegetablesWaste human food

Production system ScavengingHousehold

Current integration with fish

Wastage of manure +++

Rice milling Hand milled in the household

Notes

+ - +++; low to high


varieties and intensification can increaseavailability of bran considerably to benefit bothfish and livestock production (Box 7.L).

Benefits for the maximum number of ruralpeople probably relate to raising livestock at the

household level with the wastes producedmeeting both the needs for crop and fishproduction. Retention of rice bran by the rice-producing household is a prerequisite for pigproduction remaining a household level activity,although diversification of the diet to includeother home-produced or purchased inputs is alsoimportant. Small-holder pig rearing was formerlycommon in Northeast Thailand but is nowconcentrated in the hands of local rice millers andagro-industry. In Northern Viet Nam wherehousehold-level pig rearing remains common,production of pigs is linked closely to local feedsupplies and markets, whereas elsewhere theintroduction of mechanical rice milling byentrepreneurs in the village appears to havingstimulated consolidation and specialization oflivestock production. In turn this limits access tomanure for use elsewhere in the farming system.A comparison of ricebran use for pig productionin three areas of Southeast Asia reveals the char-

Growing hybrid maize can result in more bran aswell as a higher grain yield. Whereas localvarieties produce about 290 kg grain year-1,hybrids can produce 660 kg year-1. This meansfarmers need to plant only 0.4 ha maize tosupply a 300 m2 pond with adequate bran asopposed to 0.9 ha required if the bran derivedfrom a local variety of maize.

Source: Noble (1996)

Hybrid maize enhances integratedapproach

BOX 7.L

77 percent of households fatten pigs but only 10 percentof manure is used in the fish pond, 75 percent is used inthe ricefields and the balance for vegetables (Dinh, 1997)

Rice millers tend to waste much of their available pigwaste. In one study only 12 percent of pig producersraised fish, but more than 50 percent gave the manureaway and others sold it for fertilizing rice or vegetables

of Southeast Asia

AreaNortheast Thailand Northern Viet Nam

Rice bran Rice branBroken rice Sweet potatoesConcentrate Potatoes

Trash fishConcentrate

Penned PennedMainly peri-urban or rural resource-rich e.g. rice millers Household

+ +++

++

Milled in village ricemill, rice by-products mainly retained Milled in village rice mill, rice by-products mainlyby miller purchased back by rice grower

acteristics of current systems and opportunitiesand threats to adoption of integrated livestock-fish (Table 7.3).

More livestock – more wasteIncreasing the feed resource available is a criticalprerequisite to increase the carrying capacity ofmonogastric livestock and thus the wastesavailable for associated fish culture. Several waysexist to increase the amounts of livestock and fishthat could be produced with the current levels ofrice by-products. Mixing limited amounts of riceby-products with purchased concentrates,and/or more feeds raised on the farm e.g. cassava,maize, soybean, sugar cane, dramatically increase

the number of livestock that can be raised in thevillage, manure produced and potential fishyields (Box 7.M). Inorganic fertilization of fishponds, together with rice bran fed directly, ormanure derived from rice-bran-fed livestock alsoincreases fish yields dramatically. In a study ofintegrated farming in China, the densities of pigsproduced were clearly supported by imports ofrice by-products and concentrates into the area(Guo and Bradshaw, 1993).

Consequences of less manureDiversion of livestock waste to fish production,rather than fertilization of terrestrial crops maythreaten the sustainable output of staple crops.Even when inorganic fertilizers are available andused intensively, most farmers living in the RedRiver Delta, Viet Nam, believe that organic inputsare essential for maintaining yields. Household-level demand for manure is so strong in this area,that its relative value for fish culture must becompared to its use elsewhere in the farmingsystem. Such is the farmers’ understanding oftheir system that the balance of manure used isprobably optimal. The key role of the pig ismaintaining soil fertility in the face of decliningfertility and soil acidification is a major concern(Patanothai and Yost, 1996). The possibility ofmore pig manure being used for fish culture asrice prices decline, or small-scale and household-level pig production by rice growers is replaced


� It was estimated from a feeding trial that aherd of around 50 fattening pigs could besupported in the Northeast Thai village ofThap Hai if the animals were raised on a tra-ditional diet based on cooked rice bran,household scraps and aquatic vegetables. Ifrice by-products available in the village werereduced to only 14 percent of a total bal-anced diet that included dried cassava chipsproduced in the village and purchased con-centrate, the number of animals fattenedcould be increased to over 400.

� If the wastes were used for fish culture, esti-mated yields of 1.0-11.2 tonnes over 6months could be increased to over 12tonnes in line with changes in both quantityand quality of wastes produced. These fig-ures are based on total village level produc-tion but could be based on 100 householdsfattening 4 pigs each or 4 households raising100 pigs each. The model, however,assumes continuous milling of rice throughthe year, which in an area of highly variableout-migration practice is unlikely.

(Little and Satapornvanit, 1997)

Increasing the village pig herd in a village in Northeast Thailand-potential impacts on fish production

BOX 7.M

� Physical environments underlie the culturalvalue of livestock and fish.

� Changes in perceptions of fish culture andproduction of fish on livestock waste arepossible.

� Changes in resource use stimulated byaquaculture could have negative impacts onoverall livelihoods.

� Opportunities for resource use in aquacul-ture change in relation to the dynamics ofthe wider farming system.

Summary of key resource issues

BOX 7.N


by large-scale production by entrepreneursconcentrated spatially in the more favouredlocations, has important consequences for thesustainability of the wider farming system.Implications for competition for concentrates areconsidered further in Chapter 8.

Mixed farming systems have collapsed whenthe amount of nutrients from livestock hasdrastically declined. Although this “involution”has mainly been associated with vulnerabletropical highland areas with high populationpressures, changes to the balance of livestockand soils are occurring elsewhere. Most mixedfarming systems in the developing world have anegative nutrient balance (Steinfeld et al., 1997)and any diversion of livestock wastes to fishculture must be carefully considered. The keyadvantages of fibre-rich ruminant manure to soilfertility is through improved capacity to retainnutrients (cation exchange capacity), hold waterand maintain soil structure. Their value in fishponds is much more limited (see Chapter 5), butunder most conditions they are still the mostwidely available and used input. In Bangladesh,88 percent of farmers used their own cattle dung

as a pond input (Gupta et al., 1998), in a countrythat uses ruminant manure for fuel and housebuilding in addition to a field fertilizer.

In areas where agriculture is less intensive,such resource conflicts for manure andvegetation for feeding fish are less critical butmay also be partly attributable to the low levelsused. Indeed, the possibilities of increased use ofpond water for vegetable production probablyincreases the availability of green fodders thatcould be used both for livestock and fishproduction.

7.4.3 MACRO-LEVEL

On a regional level there are implications forpromoting aquaculture integrated with livestockor as a specialized activity, on the demand andprice of feed grains, and the consequenteconomics of livestock production. The politicaleconomy of livestock development globallyfavours the growth of vertically integratedtransnational agribusinesses producing andtrading commodities, rather than improvementsin local systems for local people. Export-led

A traditional rice mill in Cambodia. Prior to mechanical ricemills every household would mill its own rice andrice by-products were available for raising livestock


growth in agricultural commodities such asgrains or after ‘processing’ into value-addedlivestock or fish (‘seafood’) products is vigorouslypromoted by many developing countries. Littleattention has been focused on improving nutrientefficiency and reuse of wastes by suchorganizations, except where regulatoryauthorities, mainly in developed countries haveenforced it (Steinfeld et al., 1997). Typically thesolutions have been capital intensive and ‘hightech’ in approach but it should be rememberedthat resource-poor people who compete toextract and use them often add value to wastes indeveloping countries.

7.4.4 BENEFITS

Diversified production of both livestock and fishcan lower risk and improve returns on land,labour and investment. Although several studieshave shown that better-off households tend tohave more livestock and are more likely to be fishproducers (Edwards et al., 1983; Ahmed et al.,1993), integration can also benefit a range ofother people. Benefits from livestock-fishintegration can be viewed from different levels

principally those of producers, intermediaries andconsumers.

Where aquaculture is well-established andcommercialized, consumers benefit from greaterchoice and lower prices. This has clearly been thecase for urban, poorer people in Southeast Asiawhere the development of polyculturesdominated by tilapia raised on feedlot livestockwaste, have led to fish remaining affordable overthe last two decades. A survey in South Viet Namindicated that whereas richer people eat wild,mainly carnivorous fish, cheaper and culturedtilapias were favoured by the poorest (AIT/CAF,1997). In most of Africa, where production is along way from being sufficiently high to driveprices down and cultured fish are moreexpensive than alternative sources, the urbanpoor have yet to benefit in this way fromaquaculture (Harrison et al., 1994).

Poorer people in Asia often become involvedin supply and distribution networks that developaround integrated production systems.Supplying inputs such as fish seed and tradingwastes and by-products are employment nichesthat poor people quickly occupy.

Benefits to food security may be relativelymore important for household producers who are‘less successful’ at aquaculture, producing lessfish but tending to eat rather than sell them. Ruralaquaculture of this type has an important role toplay in national food security as it may be theonly way that fish can be produced in scatteredrural communities with poor infrastructure thatcannot be served by conventional marketmethods.

7.4.5 RISK

It has long been appreciated that livestock are ameans to reduce, or spread, risk for farmers(Orskov and Viglizzo, 1994). Risk aversion mayalso be an important rationale for small-holderfarmers to diversify and integrate fish production(Ruddle, 1996).

However, diversification primarily to increaseincome may be more common. Fish are generallymore like small than large livestock in terms oftheir characteristics affecting risk (Table 7.4).They are generally more marketable locally and

Electric and diesel powered ricemills have changedthe availability and quality of rice by-productsavailable to farmers in some areas of Asia


easier to add value post-harvest. The ability ofsmallholders, especially those used to seasonalabundance of fish, to deal with sudden mortalitiesand emergency harvest of fish, is typically muchgreater than for disposal of livestock. Fish alsohave lower individual maintenance, feedingrequirements which allows strategic use of scarceresources in contrast to large livestock.

Integration with fish production may reducethe risk to livestock production, or the overallfarming system on mixed farms in the tropics, inseveral ways. Although fish are more sensitive toshortages of water than livestock, theirproduction may enhance and conserve wateravailability both for livestock directly and theirfeed production. Improved stability of wateravailability is a major means for reduction of risksince fishponds often become a focus for diversi-fication. Maintaining fodder quantity and qualityfor livestock is an example of how pond culturecan reduce risks associated with ruminantproduction. Fish culture is more risky thanlivestock production in some respects. Observingand assessing the growth and survival of fish and

monitoring theft tends to be more difficult thanfor livestock, for example. However, theft of fishrequires specialist gear and skills and is probablymore difficult than stealing small livestock. Thephysical integration of livestock and fish mayreduce the costs of providing security from loss ofmany types however.

How farmers adopt fish culture as part of theirfarming system is also closely linked to theiravoidance of risk. The perception of aquacultureas being a high risk activity may lead to selectionof an unsuitable site for pond construction, ratherthan an optimal site currently used to produce atried and trusted crop. Farmers may resistproduction of livestock near or close to fishpondsif the pond is located away from the homestead.Their conservative behaviour is often explainedby the greater likelihood of theft, of both livestockand fish, in such situations. Rice farmers living onfloodplains where wild fish are still seasonallyabundant, may only stock fish in years of lowflood when both wild fish supplies are low(Gregory and Guttman, 1996) and the likelihoodof cultured fish loss through flood is least.

Large rice mills concentrate feed resources such as here in Battambang, Cambodia. This supports commerciallivestock production but may undermine household-level systems


Overstocking is common practice, both interrestrial pasture management and subsistenceaquaculture, and may derive from farmers’attempts to reduce their risk. More, if lessproductive, individual livestock or fish may be astrategy to counter risks of loss and improveopportunities for marketing in resource-poor,unpredictable environments.

7.4.6 LABOUR

Labour is often the most abundant resourceavailable on small-scale farms in Asia and under-employment is a typical feature of the ruraleconomy. The promotion of aquaculture toprovide employment opportunities is oftenadvocated but labour requirements are oftenpoorly understood. Furthermore, other activitiesmay be more appropriate to resource-poorpeoples needs. Conventional analysis of labourinputs into agricultural activities has looked at

returns to labour for different components. Insuch analyses, however, the labour inputs ofwomen and children have been undervalued andthe complexity of integration may obscureconflicts and complementarities.

The importance of off-farm employmentoptions has also often been ignored, despite thefact that if such opportunities increase in ruralareas, households adapt and food productionquickly becomes only one part of an overalllivelihood strategy. How resource-poor people atthe household level use their labour to minimiserisks and optimise gains is critical inunderstanding the potential and constraints tointegrated livestock-fish. In reality much foodproduction results from part-time farming, thecharacteristics of which are fashioned as muchfrom the type of off-farm employmentopportunities as the physical and social culturalenvironment. The nature of household-level,integrated livetsock/fish will depend on the

Factors that reduce smallholders’ risk through production of livestock, fish or both

Factor Small Large Fish Does integration reduce risk forlivestock livestock either livestock, fish or both ?

1. Feeding level required to ++ +++ + Possibly, if 7 is important. Irrigation to maintain feed availability maintain value for livestock

Integration with livestock ensures that fish are fed consistently

2. Sensitivity to lack of water + ++ +++ Water for fish can reduce water shortages for livestock

3. Local marketability ++ + +++ Local markets are more likely to be oversupplied and alternative products are advantageous

4. Easy to estimate asset value ++ +++ + If livestock are penned for more efficient integration, their asset value may be more apparent

5. Provide collectable nutrients + +++ + Use of livestock wastes for fish may reduce nutrient use for other on-farm production elsewhere, increasing risk

6. Water available to +++ See 2produce other crops

7. Opportunities for value- ++ + +++adding post harvest

8. Ease of theft + + +++

9. Ability to monitor theft ++ +++ + As above

TABLE 7.4

+ - +++; low to high


relationship between fish and non-fish farmcomponents, access to the resource base andmodern technology and will be related toopportunities for non-farm employment.

A common phenomenon related by many todeclining opportunities for integrated livestock-fish is the off-farm migration of householdmembers. Less available on-farm labour usuallyresults in modifications to farming practices butmay also result in benefits. The compatibility oflabour demands for fish culture compared tolivestock, other farm activities and off-farmemployment of various types is critical asoutlined below.

Integration to absorb labourReturns to labour in a tri-commodity on-campus,integrated farm ( livestock-fish/vegetable) werehighly favourable for fish, favourable for pigs andvegetables but less so for egg ducks (Edwards et al., 1986). The complexity of managing the

enterprises at a commercial level on a singlehousehold basis probably explains the unevenperformance and why such systems are rare. Amajor finding was that the multi-component4000 m2 farm absorbed only 34 percent of theavailable family labour despite the relativelyhigh inputs required for vegetable production.The relatively low extra labour requirement forfish culture within livestock operations probablyexplains much of their appeal. It also explainswhy livestock and fish are compatible livelihoodoptions in peri-urban areas where off-farmemployment options are more varied andflexible. Ruddle and Zhong (1988) also found ahigh level of underemployment in the ZhujiangDelta, China, at the time when management ofthe dike/pond systems were at their most labourintensive. At this time less than half ofhousehold income was derived from the dike-pond system and ‘surplus’ time available forother, often off-farm employment varied from 16-70 percent of the household labour budget. Thecompatibility of labour requirements fordifferent components of the dike/pond systemhave age, gender and seasonal aspects (Figure24). The rapid industrialization of the region,however, is contributing to a breakdown of thesystem as labour-intensive sericulture,traditionally managed by young women, hasbecome uncompetitive with factoryemployment and opportunity costs of land andwater have increased. Aquaculture has becomemore intensive, relying even more on externalinputs as such costs have risen.

MigrationMigration for work can mean long periods awayfrom the farm or short-term or seasonal absences.Household members drawn away from agriculturemay be men, women, the young or middle-aged.Migration from the farm does not necessarilymean less potential for aquaculture as it can resultin greater household capacity to invest inagriculture. However, balancing on-farm activitiessuch as aquaculture with off farm employmenttends to be easier if employment is local.

Options for off-farm employment oftenchange in tandem with a broader dynamism;traditional patterns of labour based on

Comments

Fish are cool blooded and lose condition more slowly than underfed livestock

Small units of food can generally be sold more easily

Often difficult for inexperienced fish farmers to estimate amount of fish in their pondMost important where nutrients are most expensive orleast available

The pond as an on-farm reservoir is a very important advantagein water-short situations

Sudden loss of livestock or fish may mean total loss but homeprocessing of fish products is relatively simple and the techniquesmay be well known because of seasonal surpluses of natural fish

If livestock and fish are raised close to one another guarding is more likely and risk of theft reduced

Similar to (4)


reciprocity, the roles of old and young, male andfemale, and the proportions of household andemployed labour use may all be under pressure oralready changed in response to newopportunities. Less labour is required as pondconstruction and then fish harvest have becomemore mechanized. Feeds for livestock and fishmay be produced industrially, rather than on-farm. Alternatively, labour shortages throughmigration or other causes may undermine theproductivity of, or interest in, aquaculture as itsuffers from the labour crunch. If aquaculture, incommon with other components of the farmingsystem, is marginal in terms of meeting thehousehold’s needs, it is likely to be abandoned orextensified.

Integrated aquaculture as a transitory livelihood optionAlthough increasing opportunity costs mayeventually result in small-holder, semi-intensive

aquaculture integrated with livestock becoming less competitive in certain situations,it is likely to be an important developmentaloption for the foreseeable future in manydeveloping countries. Similarly, rice/fishproduction has been adopted as a low risk entrypoint for farmers to diversify their farmingsystems in certain parts of Asia, partly becausefish culture is less labour intensive than otheroptions. Integrated rice/fish culture, however,requires significantly more labour than rice aloneand this factor has been one of the main drivingforces for farmers to switch from ricefield to pondculture of fish in Northeast Thailand (Little et al.,1996).

In one example of successful commercialegg chicken/fish system (Engle and Skladany,1992), the scale of operation meant thathousehold labour alone was sufficient and theincome produced at a level that inhibited off-farm migration. Moreover the labour

Annual Distribution by Crop of Labor Input to the Dike-Pond System of the Zhujiang Delta,China ( percent of Man-day Month-1Crop-1)

FIGURE 24Pe

rcen

tage

of

annu

al t

otal

JAN FEB MAR APR MAY JUN JULY AUG SEP OCT NOV DEC

Total

Mulberry

Sugar Cane

Fish

Silkworms

Source: Ruddle (1985)

13

12

11

10

9

8

7

6

5

4

3

2

1

0

MONTH


requirements of the chicken and fishcomponents were considered highly favourablycompared to the far more onerous on- or off-farmalternatives e.g. field cropping or constructionwork. This situation can change rapidly whenmarket access improves, land values increaseand off-farm opportunities become moreattractive, especially for younger people.Expectations of younger members of the familyare higher, especially if they have more formaleducation, and can often only be met from trulycommercial level enterprises.

The likelihood of aquaculture integrated withlivestock becoming, or remaining, an attractiveoption will be greatly affected by the cost oflabour that in turn is linked to the wider economy.As rural economies change from a subsistencefocus, the proportion of landless and resource-poor often grows. As this group typically has fewoptions in the formal economy, their employmentin the sectors such as aquaculture and livestockcan become crucial to their livelihoods. Thecontracting out of fish harvest, trading of seedand the removal and trading of wastes oftenbecome the preserve of such resource-poorpeople.

Increasing median age and declininghousehold size are good indicators of changingneed and interest in intensification ofaquaculture with livestock. Lovshin et al. (2000)evaluating retention of integrated livestock-fishin Guatemala a decade after its promotion foundreduced interest in aquaculture, partly aschildren had left home and remitted urban wagesto support older family members left on the farm.Under these conditions there was less need forincreasing fish yields and less labour to do so. Incontrast, the integration of horticulture andlivestock around small, deep ponds is particularlypopular with older people in Northeast Thailandas a method to save time and labour. Theymanage their ponds to meet their daily need forvegetables, herbs and spices rather thanoptimising fish or any other single product. Suchpeople identify the convenience, and the reducedtime and effort spent gathering such productsfrom a dwindling natural resource base, as majorincentives.

Promotion of integrated livestock-fish

7.5.1 FRAMEWORK

Promoting the integration of livestock-fishrequires a clear framework to identify majorfactors of importance, to clarify thought to directaction and to aid in communication between thevarious stakeholders.

Clarification of purpose is a critical first stepin promoting integrated livestock-fish. Is themajor objective to improve the livelihood of thelandless poor through employment andconsumption-related benefits, to stimulateagricultural labourers to integrate subsistence-level fish culture within their home plot, or tosupport commercial farmers capable ofproducing large amounts of fish for sale locally ataffordable prices? An important priority is toidentify the major beneficiaries of any promotionand clarify stakeholders that could be impactedby development. If substantive changes to bothlivestock and fish components are required,clearly the complexity is increased. The need forinterdisciplinarity, action at multiple levels(household, local, regional) and with a range ofpartners (farmers, agribusiness, extensionagents) makes the task more difficult.

Typically, attempts to promote integratedfarming have been made by technical scientists,often working within a narrow disciplinary mode.Failure to assess if promoting livestock and fish,either as single activities or integrated, isappropriate to meet the farmers’ needs andresources is common. Alternatively, grass rootsorganizations often recognise the need for, butfail to understand, the technical issues andconstraints. Although current technologies canbe improved, major impacts could be made ifexisting knowledge were promoted to peoplewith appropriate needs and resources. Limitedcapacity to assimilate technology is a majorconstraint to development in general (Juma andSagoff, 1992).

7.5


7.5.2 DEVELOPING HUMAN CAPACITY

A wide range of factors must be considered iflivestock-fish integration is to fulfil its potential.Improved policy, infrastructure and institutions atnational, and local levels are required, particularlyif poor peoples’ livelihoods are to benefit. Wheresuccess has occurred on a local basis, it is usuallyresource-richer individuals who have benefitedfrom any research and development, and agenerally supportive commercial environmentthat has sustained the practice.

The complexity and limited resourcescontributing to poor peoples’ livelihoods makesdeveloping and promoting useful information tothem particularly difficult. Facilitators withexperience in practical livestock, aquaculture,and often community development are requiredto work together if integrated livestock-fish is tobe more widely adoptable by small-scale farmers.

7.5.3 SYSTEMS APPROACH

The use of a farming systems research andextension (FSR & E) approach to promoteaquaculture lags behind its use in agriculturaldevelopment by at least a decade. Such anapproach is essential if linkages betweenlivestock and fish production are to bestrengthened.

There are three major sequential steps of

research leading towards the development anddissemination of information useful for farmers. Asituation analysis should be made initially thatassesses the needs and resources for change inthe target group, but which also includesidentification and understanding of the impactsof this change on other stakeholders. Some formof institutional analysis is also important at thisstage since sustainable development is rarelybrought about by a one–off event and theconstraints as well as potentials of responsibleinstitutions need to be understood. Identificationand refinement of appropriate technologies andmanagement through on-station and on-farmtrials is the second stage that should beintegrated with testing and dissemination of theinformation. This third stage, developingmethods to disseminate information rapidly tolarge numbers of farmers, needs invariably toconsider the complexity of the message, thenature of the audience and constraints of existingextension channels. Early identification of arecommendation domain, a targeted area orbeneficiaries with relatively uniform characteris-tics, and an iterative process relatingdevelopment of the technology with methods todisseminate it, are required.

7.5.4 FARMER-FIRST

The roles of the farmers themselves in theresearch and development process have been the

Participatory research with small numbers of resource-poor farmers in Northeast Thailand led to recommendationsthat could be promoted to a large group throughout the region. This necessitated producing stand-alone extensionmaterials that could be disseminated by the Department of Fisheries through a variety of agencies present at thelocal level


focus of a major shift over the last two decades. Atechnology driven, “top-down” approach hasbeen seen to fail especially for resource-poorfarmers in marginal environments (Chambers etal., 1989). The need for participation of thebeneficiaries in setting the development agendaand involvement in the research process hasbecome widely accepted. The need to integratefarmers’ traditional or indigenous knowledge hasbeen recognized. Focus on ecological agricultureand low external-input systems have also beenrecommended (Altieri and Anderson, 1986;Reijntjes et al., 1992). The need for a balancedview on research approach in which outsiders,depending on the context and existingknowledge base, complement the farmers’ skillshas been proposed (Biggs, 1995; FAO, 1997a).

7.5.5 CONVENTIONAL APPROACHES

The success of intensive livestock systems istestament to how the ‘transfer of technology’ hasworked for both producers of livestock and thefeed companies that support them. In regions ofhigh agriculture potential in both developed anddeveloping countries, ‘Green Revolution’techniques have resulted in quantities of feedgrains sufficient to support modern-day intensivelivestock production. Well-tested information hasbeen extended through conventional or upgradedextension services to usually better-off farmers inwell-endowed and relatively standardagroecological areas, latterly as the Training andVisit system (T&V).

The agribusiness concerns that controlcommercial feed grain and livestock productionhave used similar approaches to deliver efficient,vertically integrated production methods across ahuge range of different locations. Broiler chickensare produced in places where agro-climatic andcultural conditions are highly variable. Thisapproach requires huge resources often notavailable to governments, and has broughtbenefits mainly to more literate, better-resourcedfarmers in favoured locations.

The promotion of aquaculture as an option torecycle waste, or just to profitably utilise theborrow pits produced during construction of

livestock pens, has often been relatively straight-forward. Much of the livestock-fish production inAsia is of this nature and it has often developedwith relatively little promotion by governmentagencies.

Such ‘top-down’, transfer of technologystrategies have been less successful for extensionto more resource-poor, complex and diversesituations. Agricultural extension services oragribusiness companies in developing countrieshave often focused on ‘progressive’ or ‘advancedfarmers’, often as contact or model farmers,leaving poorer people untouched by suchservices (Box 7.Q).

Some improvements have been made thathave encouraged greater situation analysis andfarmer participation, such as the ‘Trickle DownSystem’ (TDS) promoted in Bangladesh andViet Nam (FAO, 1999). TDS is based on areorganization of the conventional extension

� Poultry-fish systems (longyam) were intro-duced into land-limited Java in the early1980s and have spread largely throughinformal mechanisms (organic spread)rather than any formal extension service1.

� In Central and Eastern Provinces ofThailand, commercial livestock-fish hasdeveloped to the extent that it is a dominantmethod to produce herbivorous fish andmonogastric livestock. A wide range of vari-ations now exist, largely as a result of farmerexperimentation and adaptation of a basicconcept to their own resource constraints oflabour, land, water, capital and market.

� Although livestock-fish systems are lesscommon in the Philippines than Thailand,raising fish with poultry in particular wasstill relatively common in a recent surveyamong commercial tilapia farmers inLuzon2.

Source: 1Kusumawardhani et al. (1994); 2Molnar et al. (1996)

Development of livestock-fishsystems in Asia

BOX 7.O


service based on training demonstration farmersand their subsequent training of fellow fishfarmers. However, the basic problem remains:effective transfer of information to poorer peopleis most difficult. Rather than trickle down, ‘trickleacross’ typically occurs, as farmers with moreand similar resource levels benefit most fromsuch farmer to farmer contact, leaving the basicproblem of more widespread involvement of thepoor unresolved. Lewis (1997) notes that despitea raise awareness of the need for partipatoryapproaches by international researchorganizations and their national counterparts,more rhetoric than change has occurred. Thesuperiority of formal scientific approaches and atop-down approach remain entrenched attitudes,while interest and understanding in social andequity issues remain a low priority.

Another fundamental constraint is the limitedcapacity of most extension services and theirfragmentation into specialist livestock andfisheries units with few links to broaderagricultural extension. Typically their staff havelimited knowledge of production systems moreappropriate for the poor, have little training in

extension methods and practices and are under-funded and poorly motivated.

7.5.6 ALTERNATIVE APPROACHES

Alternative roles for traditional extension agentsto act as facilitators and promoters to a range of‘change agents’ have been proposed (Scoones etal., 1994; Edwards, 1997). Depending on thecomplexity of the technology and the degree ofon-farm testing required, a minimalist approachmay work well in which concepts and alternativeapproaches to farm production are presentedrather than prescribed packages of testedtechnologies. Technological packages may justbe too expensive for agricultural services todevelop and provide in view of the diversity ofpossible recommendation domains (Byerlee,1987) and their value too limited in terms oflifetime.

The role of extension worker as adiagnostician and advisor on availabletechniques that can support to both livestock andfish production suggests that changes inprofessional training and management are

Methods that farmers could use to collect poultry waste were developed with them and all extension materi-als tested with farmers to ensure comprehension


required (Chambers and Jigginss, 1987). Thetraining of livestock and other rural developmentand extension staff in basic fish culture andaquatic resource management techniques wouldbe highly desirable. The potential trainingdemand for this to occur would be high.Brummett (1994) explains the advantages ofvocational training delivered locally for fieldextension staff. Given the magnitude andurgency of the job, a central role for distanceeducation for professional-level will be necessaryand would potentially meet these needs atminimum cost.

Developing capacity for promoting bothlivestock and fish by the same professionals is achallenge. Castillo et al. (1992) promotingintegrated aquaculture among small-holders inGuatemala found that, although benefits weregreater among farmers raising livestock with fish,greater technical maturity and support wasrequired from extension staff in its promotion.However, the integration of a fish productioncomponent within farms where livestock areraised traditionally can benefit the developmentof both components. Although indigenousknowledge of natural stocks is often extensiveamong rural people dependent on fish, thisusually does not extend to culture becauseaquaculture is new or relatively recent. Incontrast, husbandry of livestock, andmanagement of the resource base, are oftentraditional. An approach that values farmers’knowledge but complements it with ‘outside’knowledge will allow people to learn about fishculture through their experience with livestock;and concepts introduced with fish can, in turn,educate their views on livestock production. Theneed to make changes to long-established,livestock management practices because fishculture, as a new component in the farmingsystem, requires it, can act to stimulate positivechange of the traditional system. Introduction ofimproved waste management primarily to ensureadequate inputs for fish production can alsoimprove the health status of livestock.

Traditional livestock management conceptssuch as nursing and fattening can be useful inimproving management of fish. In Lao PDR, alivestock extension network has evolved to

support farmers’ efforts in raising fish (Innes-Taylor, Unpub). The cold chain developed todeliver livestock vaccines is also used todisseminate hormones for farmers to breed theirown fish and assure local fish seed supply.

In practice adoption of fish culture throughfarmer-to-farmer extension can be stimulatedthrough a range of change agents and theapproaches and motives to improve fish,livestock or crop production interact.Surintaraseree and Little (1998) found thatrice/fish farming spread in Northeast Thailand inthis way, and that farmers’ holistic view of theirsystem meant that benefits occurred directly andindirectly through livestock, crop and fishcomponents of their system.

In the same region, written information onsimple technical interventions involving the useof livestock waste and inorganic fertilizers in fishculture has been taken up by up to 55 percent offarmers receiving materials (Turongruang et al.,1994). Moreover, as this approach did not requirecontact with an extension agent, informationcould be delivered through non-specialistchannels at low cost. The private sector can alsoparticipate in this process. Commercial mediadisseminate information as attractively packagedtechnical articles on television and printed form inmany countries. Institutional structures are oftena barrier to this type of innovation and even whena more farmer-first approach is accepted,implementation can be slow or ineffective. Thespecialized education that professionals receivehas been identified as one reason (Chambers,1993) but the cultural norms of institutions andthe wider culture typically accentuate theconservative view. Narrow outlooks on productionsystems also require broadening to encompassthe wider resource system and an understandingof rural peoples’ livelihoods (Edwards, 1997;Carney, 1998). (Box 7.R) Decentralized and morepro-active institutions are required if progress isto be made in improving access to relevantinformation by poor people.

Problems in the promotion of aquaculture orthe integration of livestock with aquaculture arenot unique and need to be put in perspectivewith success in other fields of rural development.Harrison (1994) noted that ‘the legacy of previous


� Aquaculture is not traditional in Thailand.Peoples’ appetite for fish to complement adiet of rice and vegetables was metthrough capture of wild fish and a host ofother aquatic animals until relativelyrecently. Chinese immigrants introducedaquaculture, of common carp, andChinese carps, in the early 20th centuryalthough cultivation of native fish e.g.Pangasius hypothlalmus, Oxyeleotris mar-moratus and Trichogaster pectoralis, on asmall-scale may pre-date this practice(Edwards et al., 1983). It was only withthe decline of the wild fish harvest and astechniques for the controlled breeding ofthese species became known that theirculture became more widespread. In the1930s attempts to popularize the cultureof Trichogaster, failed. Culture of tilapiasin ricefields and ponds was promoted inthe 1950s, and people were encouragedto raise fish together with pigs and poul-try. One pamphlet describing how to cul-ture tilapia sold over 300 000 copies intwo editions at the time (Edwards et al.,1983). Irrigation projects were also begin-ning to have a major effect on the avail-ability of natural fish stocks in theChaophraya basin that dominated CentralThailand, especially after the completionof the Chainat Dam and distribution sys-tem in the early 1960s.

� In the first detailed survey of its type, itwas found that aquaculture, in a variety offorms, was practiced by around 3 percentof farms in one central province, PathumThani by the early 1980s. Integrating live-stock, especially pigs but also chickensand ducks with fish culture had becomeestablished in the early 1980s; most prac-titioners began five years prior to the sur-vey. Longer established operations were

concentrated around the central provin-cial city. Farmers continuing to producerice and raise fish as a minor crop weremuch less likely to integrate livestock withfish. Farms raising fish for between 10-30years were more often diversified andoperated by farmers of Chinese descent.

� During the 1990s, as Thailand’s industri-alization accelerated, the centre of inte-grated farming has moved outwards fromBangkok as land values have soared andfactories and residential areas have devel-oped. Integrated livestock-fish has grownrapidly in response to market demandgenerated by urbanization and rising pur-chasing power. Initially beneficiaries weremore urbanized people, closest to infor-mation, inputs and markets but recenttrends indicate the entry of rice farmersinto aquaculture, after conversion of ricefields into shallow ponds. Pig and chickenmanure is purchased or removed freefrom nearby intensive operations andoften transported by middlemen. In theselivestock-dense areas of Central Thailand,livestock farming at the scale requiredneeds high investment, but pond cultureof fish has much lower capital costs, espe-cially as the cost of mechanically con-structed ponds has steadily declined.Improved market access and road infra-structure has also reduced the entrycosts, opening fish culture as an optionfor a wider range of farmers. Knowledgeabout raising livestock and fish togetherhas been disseminated in the media andthrough vocational training. Credit, oftenfrom Government agricultural banks, isnow also more widely available.

Development of integrated livestock-fish production in the provincesaround Bangkok, Thailand

BOX 7.P


development interventions has a profoundinfluence on the way that rural people respond tonew ones’ with regard to adoption of aquaculturein Africa. Many of the problems that have besetextension of aquaculture and its impact in ruralcommunities, be they poor rates of adoption or‘low’ output, are common to ‘top-down’development initiatives in other sectors.

7.5.7 EXTERNAL FACTORS

The adoption of integrated livestock-fish hasbeen uneven throughout the developing world,

even in places with suitable agro-ecologicalconditions. Sustained periods of warmtemperatures are required for the most efficienttreatment of organic wastes but in practicesuccessful integration occurs across a widerrange of environments. Where the practice hasbecome established, and is today mostsignificant, overall economic and infrastructuraldevelopment have been more important thanformal extension. A historical dependence on fishis far more important than any tradition ofaquaculture as the rapid adoption in Thailandhas shown. In certain areas e.g. West Java and

� Farmers who adopted, and benefited from,integrated livestock-fish in Pathum Thani bythe early 1980s were a small rural elite withsignificant resources. The relative poverty ofthe majority of farmers growing rice in thesame Province stimulated the concept of scal-ing-down livestock-fish farming to meet theneeds and resources of ordinary rice farmers.Rice farmers, especially those with poorlydiversified farming systems, were more likelyto seek off-farm employment, and consumedsignificantly less fish than average. The ration-ale of introducing livestock-fish systems wasto improve both household nutrition andincome. Both on-station and on-farm trialswere run to develop a technical model thatcould be managed and sustained by resource-poor farmers. Farming households wereactively involved, participating in pond con-struction and provision of a proportion of thelivestock feed. The researcher-managed trialsfollowed a structured design that farmers fol-lowed, and there was little flexibility orinvolvement in decision-making. Egg-layingducks were chosen as a suitable type of live-stock, as a preliminary assessment had foundduck eggs to be readily marketable in the vil-lage and their integration with fish culturetechnically feasible using locally available

materials. A standard design of pen that keptthe ducks enclosed over the pond water at alltimes ensured that all the manure and spiltfeed entered the pond. If ducks are allowed toscavenge for a portion of their own feed, ponddikes quickly become eroded, and much ofthe waste lost. On-station research found that30 ducks kept in this way over a 200 m2 earth-en pond stocked with Nile tilapia for 6 monthsproduced enough fish to meet all the estimat-ed animal protein requirements of a family offive.

� Unfortunately, once support for the purchaseof livestock feed was withdrawn, the farmerswere unable to sustain the system. The rationgiven to the high-yielding ducks had to bepurchased as the farmers’ own paddy rice wasunsuitable for inclusion in the balanced dietrequired to maintain egg-laying rates at eco-nomic levels. Most families found managingthe high level of inputs and outputs difficult.A regular cash outlay for feed was requiredand the large numbers of eggs produced dailywere difficult to market. The relatively largeamounts of fish produced were greatly valuedbut the system did not fit within the farmers’overall resource base, with cash and timebeing particularly limiting.

“Top down” small-scale duck-fish integration fails

BOX 7.Q


the Philippines, high land costs and a relativeabundance of large water bodies appears tofavour the development of cage-based operationsbut pond-based fish culture has also continued todevelop, particularly in West Java with fewerproblems of land tenure for small-holders than thePhilippines.

In countries where economic conditions aresuitable and an entrepreneurial class has accessto land and water, integrated livestock-fish canspread with relatively little formal support, atleast among better-off farmers. Technologytransfer by agribusiness has been effective in thetransfer of modern intensive livestock systems,and if other resources and market opportunitiesare suitable, entrepreneurs have quickly used thewaste for aquaculture and/or horticulture (Box7.P). Where integrated practices have becomeestablished such as in Thailand, the media and

agribusiness have supported information flowand wider economic development has stimulatedintensification of livestock production.

� The ancient hydraulic civilization located inthe dry zone of Northwest Sri Lanka wasbased on ‘tank’ irrigation. The storage of rain-water in ‘tanks’, large, man-made reservoirs,within watersheds that could be used to irri-gate the crop of rice was critical to reducingvulnerability to shortages of water and alsoprovided an important source of fish. In thelast century these systems have been rehabil-itated and watersheds have become moredensely populated. The pressure on theresource base has intensified, especially asthe water held in these community-managedtanks is used for a variety of purposes. Mosthouseholds rely on them for domestic watersupply, and in the dry season they become animportant grazing and water resource for live-stock in addition to their primary purpose tosupply irrigation water for the rice.

� The tanks, arranged as a complex mosaic with-in watersheds, interact in terms of movementof both water and fish through the seasons.

As the rains begin and the upper watershedtanks fill, they begin to overflow into thecatchment of the tanks below. This allowsupward migration of aquatic animals to repop-ulate upper tanks that may completely dry outduring the dry season.

� Understanding how individuals from commu-nities gain access to, and benefit from, theseaquatic resources is complex. Their intensifiedmanagement is a challenge. The nutrient linksbetween management of grazing livestockand fish are clearly important and a majordeterminant of overall productivity.

Working with communities surrounding differenttanks in the same cascade to improve livelihoodsrequires an interdisciplinary approach tounderstand and resolve potential conflicts. Astakeholder approach that builds on anunderstanding of the resource base and theinteractions between the various components is auseful way to realise the potential of thesesystems for equitable development.

An approach to understanding constraints to fish production in rain-fedcascade tanks systems in the Dry Zone of Sri Lanka

BOX 7.R

CHAPTER 8 • TRANSFERABILITY OF ASIAN EXPERIENCES TO AFRICA AND LATIN AMERICA 131

Transferability of AsianExperiences to Africa and Latin America

8

The widespread belief that rural aquaculture has been

proven to be more appropriate in Asia than either Africa or Latin America is reviewed.

A range of shared constraints to adoption of aquaculture has been identified,

especially when integrated with livestock, using evidence drawn from evaluations of

development projects on the three continents. We firstly consider the general status

of aquaculture development and identify common features, before considering

information needs for successful adoption of rural aquaculture and the institutional

constraints to their development and delivery.

Solving the problems of poor fish seed supply andlosses through theft and predation are asfundamental to successful adoption ofaquaculture by small-holders in Asia as well asAfrica and Latin America. The role of culturedfish in meeting the needs of rural people iscompared, and many similarities identified,especially the reliance of fish pond water todiversify and stabilise surrounding farmingsystems. Benefits from aquaculture within thehousehold and to non-producers are alsointerpreted from developments outside Asia.Attempts to promote aquaculture on acommunity-level basis have been made in manydeveloping countries and post-project

evaluations of several projects allow some broadconclusions to be drawn.

A summary of some key factors that explainsthe apparent dichotomy in integrated livestock/fish development among small-holders in Africa,Asia and Latin America concludes the section.

General considerationsThe broad developmental challenge in bothAfrica and Latin America is similar to that inAsia: populations are rapidly increasing and

8.1


environments, and thus the means to supportincreased numbers of people, are degrading.Although both mean population densities andabsolute numbers of poor people are lower inAfrica and Latin America than in Asia, acutepoverty and highly inequitable development iscommon to all three continents. Various casestudies of attempts to promote aquaculture as

stand-alone or integrated activities suggest thatmany of the constraints and opportunities aresimilar. A superficial review can quickly result ina conclusion that attempts to promote small-scale aquaculture in Africa and Latin Americahave failed and have little future. However, oneholistic analysis of the causes of failureconcluded that fish culture can become

TABLE 8.1Issues and problems from the perspective of aquaculture promoters in Africa, Latin

Issues/Problems Explanations/Comments

1. The development context •projects have an aquaculture focus rather than being needs-driven

•both needs identification and making the links between these and aquaculture is problematic

• lack of awareness of off-farm factors and other livelihood options

2. Lack of sustainability of project • inadequate assessment of limitations and priorities of host institutionefforts, including collapse of • inadequate involvement of all stakeholders in needs assessment and probleminfrastructure identification

• infrastructure development focus

3. Problems in extension services: • lack of incentives, little participation in decision-making, dependence on allowances

•poor morale • training has been technically and fisheries-based

•unable to reach farmers

•inappropriate advice

4. Weaknesses in monitoring and •lack of clarity concerning overall objectives and mechanisms for their achievementevaluation •failure to incorporate intra- and inter-household resources

•lack or inconsistent data collection

•projects over focus on data collection; unreliable and inconsistent data storage and use

•lack of understanding of demand and benefits to consumers5. Farmers do not respond as hoped: •aquaculture may be attractive and adoptable by only a limited number of farmers

•failure to adopt •fish production below the technical optimum may meet farmers’ needs

•poor management •water resource development may stimulate other uses of water that meet farmers’ needsbetter

•better technical advice/knowledge base required by farmers for improved yields

•limited capacity to improve yields because of resource constraints, physical factors etc.

•better-off farmers benefit most, poorest people least


established as a valuable part of rural economies(Harrison, 1994; Brummett and Williams, 2000)and this has subsequently been demonstrated inparts of southern Africa (Van der Mheen, 1998).Another issue is the degree to which success isoften measured in terms of project outcomes,which can be different to evaluation in terms ofthe needs of farming households. Many farmers

in Asia have begun aquaculture without contactwith foreign or government sponsored ‘projects’and evaluation of impacts of individual projectscan obscure a broader-based phenomenon.

Aquaculture in Africa and Latin Americacovers a wide range of culture systems withinvariable social, economic and ecologicalconditions. The promotion of rural, pond-basedaquaculture in both regions has often failed, ashave many other aspects of rural development,through misconceived foreign aid projects thathave not focused on the real needs of thebeneficiaries.

Progress in developing integrated livestock-fish in both rural Africa and Latin America hasbeen slowed by a failure to recognise and adjustto failure (Harrison et al., 1994). Althoughaquaculture in sub-Saharan Africa produces atiny proportion of the world’s cultured fish <0.5percent (Lazard and Weigel, 1996), aquaculture istraditional in Ghana (Prein and Ofori, 1996) andelsewhere and survives in subsistence form inmany countries. It remains an important potentialfocus for rural development. Demand for culturedfish varies greatly in Africa, depending on thevalue of fish as a regular food item and theavailability of natural fish stocks or cheapimported fish (Lazard and Weigel, 1996).

In certain countries of Africa and LatinAmerica with suitable infrastructure andinternational connections, high-input intensiveaquaculture geared towards export has becomeestablished. Atlantic salmon in Chile andintensive cage and raceway-based tilapiaproduction in Zimbabwe and Costa Rica,respectively, are well-established, typically in avertically integrated mode that parallels that usedfor broiler chicken. In Columbia, growth indemand by better-off consumers has made feed-based aquaculture an alternative investment tomonogastric livestock. In such cases, richerpeople control both production and consumptionand the impact of the industry on poorer people isminor.

A comparison of the development of fishculture in Asia with Africa and Latin America interms of the perspective of both the promotersand the farmers is instructive (Table 8.1). Itsuggests that many of the constraints to adoption

America and Asia

Recommendations

• participatory research on needs for and value of aquaculture in specific contexts

• see 3 below

• livelihood analysis

• understand institutional legacy: how and why projects fail

• stakeholder analysis

•assess proposals for infrastructure in light of potential to meetdevelopment needs

• focus on institutional strengthening including managerial trainingand planning capacity

• revise project approaches to make them more flexible

• Reassess options for developing and extending information to farmers

• encourage private sector options

• ensure that aquatic resource R and D is incorporated into generalrural development extension models

• ensure that aquatic resource R and D is incorporated intogeneral focus training locally and towards participatory approaches that seek to strengthen linkages with ARM in overall livelihoods of the poor

• introduce relevant and measurable indicators

• needs analysis of target group and responsive extension advice

• careful selection of target group for promotion of aquaculture


of productive aquaculture are similar, as is theintegration of fish culture with livestock. Animportant point is that development ofaquaculture in the three regions has not beenhomogeneous; the level of aquaculturedevelopment in Cambodia among poor ruralpeople is little different to that of similar groups inmany parts of Africa and Latin America.

High demand for fish, often relatedhistorically to high human population densities ofriver valleys and deltas, and a reliance by suchflood-affected people on fish to meet nutritionalneeds, has clearly been an important stimulus toaquaculture. Rural population densities in Africacan reach levels found in Asia and in such areasa greater reliance on livestock and their manuremanagement is found (Lekasia et al., 1998). Suchpopulation concentrations tend to be in highlandareas, such as in the Kenya Highlands, where

there is less traditional reliance on fish however.However, aquaculture is largely a recentphenomenon in Asia, even in areas where it isnow common (Edwards, 1996; Lewis, 1998).Small ponds, often the result of the removal of soilfor construction, may be a more common featureof land-holdings in flood prone areas of Asia. Thisinevitably reduces entry costs and risk, makingattempts at fish culture more attractive. InMalawi, even small ponds are uncommon and animportant investment for average small-holders,the majority of which have land-holdings of lessthan 1 ha (Noble, 1996).

Aquaculture development to meet local needsfor food fish can be categorized into three stageson all three continents (Box 8.a). The recentacceleration in uptake of rural aquaculture overthe last two decades in areas where it hasoccurred traditionally, may be linked to earlier

Despite differences in current status ofaquaculture and its perceived success, the needsand constraints of smallholder farmers that couldpotentially adopt aquaculture as part of theirlivelihood strategy in rural Africa and LatinAmerica are remarkably similar to Asia.

STAGE 1� Little aquaculture adoption, enough wild fish.

Early adopters are entrepreneurs, often ethnicor religious minorities. Limited demand,indigenous fish preferred.

STAGE 2� Early adopters become seed producers; com-

petition among food fish producers stimulatesintegration with livestock and other resourceuses.

� Secondary, more numerous adopters of aqua-culture, many retain a subsistence approachand ponds are multipurpose. Characterizedby a broadening range of how aquaculturebenefits people, especially the poor, throughservice and consumption. A minority develops

towards a more commercial focus.

� Vertically integrated operations introducedbut often fail as market conditions are unde-veloped.

STAGE 3� Shrinkage in number of operators as low

input-output fish production has a furtherreduced role in livelihood systems; more off-farm labour, better infrastructure reduces roleof pond as on-farm reservoirs and food pro-duction generally.

� Commercial and vertically integrated con-cerns compete, driving price of fish down.Sustainability of household-based commercialproduction and integration with livestockdepends on ‘macro’ factors such as feedprices and environmental controls.

� Early adopters may use assets to diversifyaway from food fish production to ornamentalfish production or unrelated services,urban/professional livelihoods.

Stages in aquaculture development to serve local demand

BOX 8.A


adoption by a small minority and these may bemore numerous and concentrated in Asia thanelsewhere. Examples of all three types may befound in Africa, Latin America as well as Asia.

Information needs The need for appropriate information to allowhouseholds with few resources to adoptaquaculture ‘successfully’ has rarely beenappreciated by promoters. Some observers havelinked the failure of African aquaculture to anabsence of a tradition of livestock management ingeneral in which fish are treated in pondssimilarly to small livestock i.e. left to fend forthemselves and used for special needs (Hickling,1971; Harrison et al., 1994). But this is a similarsituation in much of Asia where there is also littleindigenous knowledge about aquaculture amongthe many rural households for whom it could bean option. The key gaps of knowledge that affectAfrican farmers also inhibit small-holder fishculture in Asia. Commonly, people dig ponds withinitial enthusiasm but little or no nutrients areused in the pond and fish yields are low. Suchunder-fertilization, either through poor access tonutrients or limited understanding of the concept,often leads to expectations remaining unfulfilled.Poor stock management in which seed with lowresistance to predation are under or over-stockedis also common. This again may partly be relatedto a lack of knowledge but it may also indicate thefarming household’s motivations as indigenouscarnivorous fish may be preferred to cultured fishspecies. Lewis (1997) reports that lack ofknowledge rather than credit constrained poorhouseholds managing small ponds and ditchesprofitably for aquaculture in Bangladesh.

Prolonged culture cycles are also awidespread phenomenon. The tendency forfarmers to hold fish for extended periods has beenrelated to the pond being viewed as an asset andas a savings bank rather than as a unit ofproduction. Poor harvesting technique orequipment and a lack of knowledge about growthand breeding patterns have also been implicated

(Harrison et al., 1994). A similar tendency iscommon among small-holders in Asia, for whomthe pond is an important social asset as a larderor convenience store, especially if regular foodneeds are met in other ways. Usually, andespecially where the culture of wild fish istraditional, the availability of skills and materialsto catch fish is not a constraint. However, thewidespread availability of very cheap modernsynthetic net material in rural Asia may be animportant difference to large areas of Africa andthe Americas.

Institutional constraintsThe capacity and sustainability of institutionsworking to promote aquaculture are key factors ofsuccess or failure. A major constraint toinstitutions working effectively to improve poorhousehold’s nutrition and income throughaquaculture has been their technically-ledapproach (AIT, 1994). This is an aspect commonto development efforts almost everywhere. Untilrecently, this was the case as much for nationalagricultural research centres as for internationalagencies. Furthermore, linkages and ‘activepartnerships’ have often been lacking betweenthese types of institutions and field-levelorganizations that have contact with largenumbers of rural households. Lewis (1998)describes the institutional constraints to effectivedevelopment for the poor in Bangladesh underconditions of ‘resource constraints’, notresources constraints for poor farmers but forcompeting professionals, and this country hasone of the developing worlds’ best financedprogrammes for promotion of rural aquaculture.As Lewis (1998) wrote: ‘it is tempting to suggestthat ICLARM and FRI need each other far morefor the individual institutional survival of eachagency than the average low income farmhousehold in Bangladesh needs new technologyfor aquaculture’.

Although participatory methods that workwithin the social and economic constraints of thetarget beneficiaries are required, a lack of

8.3

8.2


relevant, generic information has been a commonneed of grass-roots development organizationsworking with farmers almost everywhere. This isoften as true for livestock development as foraquaculture. Applying concepts, techniques andmanagement to specific conditions inpartnership with the beneficiaries is a complexand highly skilled task. A major problem is thatthe skills to do this are not taught at mostuniversities or colleges; the much greater rangeand availability of institutions deliveringeducation in aquatic resource management inAsia than elsewhere has not returned theexpected benefits. Typically the focus is naturalsciences alone and Masters level graduates havelittle if any direct experiece at the village pondside (Lewis, 1997). Improved training of field-levelstaff that focus on holistic and interdisciplinaryskills are an urgent need throughout lessdeveloped countries.

As a general rule, human resourcedevelopment precedes natural resourcedevelopment and this is best carried out locally(Brummett, 1994). The current reliance on limitednumbers of poorly trained and motivatedextension staff to promote aquaculture occursthroughout the developing world. This has been amajor constraint in both Asia and Africa. Forexample, the national country-wide extensionservice in Bangladesh is based on one extensionofficer in each thana, a local government unitwith about a quarter of a million people (Lewis,1998). Perhaps inevitably, especially asproduction targets rather than poverty reductionhave tended to drive extension efforts, the focusin many countries has often been on richer, moreaccessible farmers.

Regular and prolonged contact does notnecessarily result in effective adoption, especiallynot if the farmers’ needs were ill-understoodand/or extension agents’ informationinappropriate. The lack of long-term, field levelimplementers in a project in Guatemala wasidentified at the time as a major constraint tosuccess (Castillo et al., 1992), but post-projectevaluation has recently suggested that lack oftechnical knowledge was not the major reason forfarmers neglecting or abandoning fish culture(Lovshin et al., 2000).

Highly dispersed, rural households has beenassociated with the difficulty of effectiveextension in Africa but such conditions are alsocommon to many under-resourced, conventionalextension services in Asia. On-farm, group-basedtraining is an effective and practical solution andalso an approach that has proved more relevantand cost-effective in places with higherpopulation densities. Even when limited budgetsfor field-level, extension staff and operatingbudgets have constrained the impact ofprogrammes to actively promote fish culture inrural areas, a consistent presence can, over time,be an important stimulus and support for earlyadopters. This has been demonstrated by bothgovernment and non-government efforts inNortheast Thailand (Little and Satapornvanit,1996).

Similar problems that have confrontedinstitutions attempting to promote aquaculturein Asia have been identified for the other tworegions. Indicators of rejection of fish culturesuch as abandoned ponds and sub-optimal fishmanagement are as typical of rural Asia as theyare of Africa and Latin America.

In the past, there was a similar emphasis onrenovation and rehabilitation of Governmentponds, farms and hatcheries without considera-tion of their effectiveness and their longer-termsustainability. Planning to ensure realisableobjectives, operating budget and staff motivationhave often been insufficient. Prevailing institu-tional cultures that are not responsive to theneeds of poor farmers in rural areas are often afundamental problem. Such factors have oftenbeen made worse by aquaculture being locatedwithin fisheries departments or D’eaux et Foret,rather than within a broader agricultural exten-sion service (Harrison et al., 1994; FAO, 1997a).

Development of managed aquatic resourcesis not usually part of a coherent national plan andopportunities for synergism are lost; aquaculturein particular, is typically accorded low priority.Structural adjustment, or roll-back of governmentsupport for extension also takes a toll on theconventional extension approach. Even whenfisheries development is accorded a high priority,performance is often affected by a limitedcapacity of the institutions to plan and manage,

and poor co-ordination within and betweenorganizations, including many internationallyfunded and staffed donor projects.

Better integration of institutions promotinghousehold-level livestock and fish culture couldhave many tangible benefits, particularly inpoorer countries with few resources. This hasbeen demonstrated in the Lao PDR whereresponsibility for extension of livestock and fishproduction by the same local level extension staffhas proved beneficial (Innes-Taylor, pers comm.).

Research is typically separated from extensionand focused towards on-station, bio-technicalissues rather than being responsive and problem-orientated. Even if research on ‘low input’ systemsis prioritized, on-station research will still oftenmis-target research efforts (see Box 8.B).

Many of the institutional constraints todevelopment are exacerbated by the projectapproach of foreign donors. Indeed the complexityof issues, mixed motivations and negative

interactions between various ‘partners’ indevelopment projects are often major causes offailure to impact positively on targetbeneficiaries. The need for leadership from localactors rather than external development agenciesper se has been identified by Brummett andWilliams (2000) as a key requirement to stimulatesuccessful rural aquaculture. Generally in Asiathis has not required ‘research’ but rather theintroduction of ideas and concepts and theiradaptation by progressive farmers.

The ‘critical mass’ among the private sectorin large parts of Asia is now a major driving forcefor development. It can give the impression thatinstitutional constraints were, and remain, lessimportant here than in Africa or Latin America.However, adoption of aquaculture by poor peopleremains far from complete in Asia andinstitutional constraints are, as in Africa andLatin America, are of major importance andlargely unresolved (Box 8.C).


� Standard recommendations for semi-inten-sive aquaculture in India were highly suc-cessful for resource-rich farmers in AndraPradesh but largely irrelevant for theresource-poor.

� Fertilizer regimes developed at AIT for opti-mal production were not adopted by a largeproportion of risk-averse farmers inNortheast Thailand, despite proven andpotentially high returns (Turongruang et al.,1994). This has since been exacerbated bythe recent economic crisis which resulted ina sudden and steep rise in the price of inor-ganic fertilizers.

� Project-based research aiming to supportfish culture by smallholders in Central andNorthern regions of Malawi was based onanimal manures that were practicallyunavailable to the farmers.

Source: Dickson and Brooks (1997)

Poorly targeted research forresource-poor farmers

BOX 8.B

� No review of history and mistakes.

� Emphasis on infrastructure rather than solv-ing persistent managerial/technical prob-lems.

� Focus on over-ambitious fish yield targets;often not set in any framework of overallnutritional/cash needs.

� Lack of realistic and measurable indicators.

� Extension service become data collectors forsophisticated, unsustainable data-bases.

� Poor quality of training for extension staff,dissemination of inappropriate messages.

� Extension staff mainly biologists not trainedin extension.

� Close linkage with fisheries rather than agri-cultural extension.

� Promotion through unsustainable provisionof inputs and services.

Institutional issues constrainingaquaculture development commonto Asia, Africa and Latin America

BOX 8.C

Seed supplyPoor seed supply has been a major constraint tosustainable adoption of fish culture in all threeregions. Adoption of fish culture in the past intraditional areas of Asia depended either oncapture of wild seed of Chinese and Indian majorcarps from rivers, or household-level spawning ofcommon carp. Induced breeding of carps in the1960s led to available seed of these species, atleast adjacent to large, central hatcheries. Afocus on self-sufficient strategies based onmixed-sex tilapias has been most successful inmany countries in both Africa and Latin Americaand they have also proved important in much ofAsia. Technical specialists have long perceived areliance on tilapias that breed within the culturesystem as both a handicap and opportunity forthe development of aquaculture in Africa (Lazardand Legendre, 1996). Alternative species, whichare more dependent on government hatcheries,such as carps and catfish have proved lesssustainable. Projects in Cote d’Ivoire, CentralAfrican Republic, Congo, Cameroon, Madagascarand Niger promoting aquaculture around a fryproduction facility found a number of commonconstraints (Box 8.D), but these have also beenidentified as being relevant in much of Asia(Shrestha et al., 1997). Where private sectorhatchery production was stimulated, as in Coted’Ivoire, and 60 percent of the fish stocked by theproject were produced by farmers, continued sub-sidised central production probably constrainedthis private sector development. The same

situation was also found in Northeast Thailandbefore private sector fry production boomed in themid to late 1980s (Little and Muir, 1987).

Poor seed supply has undermined project-led,aquaculture promotion in Latin America andAsia. Government hatcheries were unreliablesources of seed but attempts to promote self-sufficiency among farmers, even of mixed-sextilapias, met with uneven success (Box 8.E). Ifgovernment-based carp seed production hasproved largely unsustainable in Africa and LatinAmerica, its success has also been patchy inAsia. It is likely that poor demand for exotic carpshas often been underestimated as a major causefor this failure, which occurred in countries suchas the Philippines and Sri Lanka. In countrieswhere riverine carps are indigenous, such asChina and India, their controlled reproduction

8.4


Tilapia culture was promoted in both Panamaand Guatemala to encourage self-sufficiency ofseed and reduce dependence on governmentsupplies of carps:� supplies of carp seed from government

hatcheries in Panama were unreliable, com-munity pond operators were trained intilapia seed production techniques;

� after 14 years, most projects still raising fishwere not self sufficient in tilapia seed andremained dependent on the government forrestocking;

� a lack of water, difficulties in managing fryproduction on a community basis, and con-tinued availability, often subsidised, of seedfrom the Government were major reasonsfor this;

� smallholders continuing to stock carpsremained dependent on government sup-plied seed in Guatemala. Most of the aqua-culture sustained was based on stockingmixed-sex tilapia obtained locally.

Promoting self-sufficiency of fish seed

BOX 8.E

� High operating costs of Government stations.

� Low levels of technical expertise.

� Logistical problems in dissemination of seedto farmers.

Source: Lazard and Legendre (1996)

Constraints to fish seed production in Africa

BOX 8.D


and that of other introduced carps becamerapidly established within the private sector.Countries in which distribution of wild caughtseed through trading networks pre-datedhatchery development, such as Bangladesh andViet Nam, witnessed a particularly rapid spread.

Theft and predationTheft is a commonly mentioned risk to small-holders fish culture, restricting its adoptionthroughout the developing world. The fact that‘theft’ may actually be caused by predation ofcarnivorous fish, mammals and birds is oftenoverlooked. Theft from ricefields stocked withfish was a common constraint in Thailand andelsewhere where traditionally only the rice wasindividually managed and other foods commonproperty (Little and Satapornvanit, 1996).‘Redistribution’, either through purposeful theftor accident through flooding to neighbours orextended family, is also common in Africa andAsia. Aquatic environments make fish and otheraquatic products more difficult and risky tomanage than terrestrial crops. Escaped fish arealmost impossible to reclaim as they cannot beeasily marked for identification. Individualgrowth and survival is problematic to monitor,making strategic theft hard to detect.

Proximity of cultured fish to the homestead,or availability of male household members toguard isolated ponds, are important factorsreducing the risk of theft, however.

DemandThe motivations for attempting aquaculture bysmall-holders in Asia mirror the range observedby Harrison et al. (1994) in Africa. Generallyfarming households will view the pond, and thefish in it, as part of a portfolio of assets andopportunities. Their strategies for managing and

using the water, fish and other products dependon their resource base and needs. The availabilityof other livelihood options and relevantinformation are also critical to determining howfarmers use their water resource. Farmed fish arean asset that can be used directly for homeconsumption or reducing cash expenditure onfood. Easy access to cultured fish can also reducethe time spent catching wild fish. Products fromthe pond may be sold, bartered or given away, inexpectation of later reciprocation.

The reasons for agencies to promote, and forthe farmers to adopt, aquaculture are complex.The idea that successful small-scale aquacultureis commercial in Asia, as opposed to subsistencein Africa (Hecht, 2000), is simplistic. Lowpopulation density, abundant land and demandfor fish initially motivated households to tryaquaculture in Luapula, Zambia. Farmers wereless concerned with fish production becoming asource of income than other factors. In contrast,resource pressures made income generation themain motivation for digging and managingponds in Western Kenya. Markets and marketchannels were also better developed in the latter(Harrison, 1994). A similar contrast could bedrawn between the market responsive farmers ofNorthern Viet Nam and subsistence-focusedhouseholds in less developed and populated partsof Southeast Asia. In the subsistence economy ofRwanda, Hishamunda et al. (1998) found thattilapia culture benefited household welfare muchmore through income generation rather thanhome consumption as an enterprise within thefarming system.

The amount of fish cultured by householdsmay have less impact on diets and income thanis often assumed. In Africa, farmers mostsuccessful at producing fish also obtainedsignificant quantities of fish from wild stocks andmarkets (Harrison et al., 1994). Fish culture hadless impact on their household food security thanhouseholds producing less fish themselves, butwith poorer access to alternative sources.Aquaculture was promoted in NortheastThailand for decades before the impact of therelatively small amounts of cultured fish wereplaced in context with the generally far more

8.6

8.5


important quantities of fish purchased or caughtfrom the wild (Prapertchob, 1989; Little andSatapornvanit, 1996).

Demand for any type of food reflects culturalnorms, availability of substitutes as well aspurchasing power and resource wealth. In muchof Southeast Asia, fish consumption, by choice,can reach levels of 60 kg. caput-1 year-1

(Sverdrup-Jensen et al., 1992). Clearly, ruralhouseholds raising fish often have a range ofoptions. Subsistence may still be the majorobjective of small holders raising fish, even whenfish is highly marketable locally. More than half offarmers stocking fish in Northeast Thailand sellno fish (AIT/DOF, 2000) and Lovshin et al. (2000)found that a similar proportion of smallholder fishculture in Guatemala was subsistence-based.Farmers may also view entry into aquaculture asan option to reduce risks associated withdeclining abundance of wild stocks or tosubstitute cultured for more valuable wild fish inthe diet (Box 8.F).

The need to intensify either livestock or fishproduction to meet food security and cash needsis still undeveloped in parts of both Africa and theAmericas, but this reliance on naturalpopulations or extensive production methodsalso remains the case in parts of Asia (Little andEdwards, 1997). Traditional livelihoods have oftenbeen affected by opportunities in urban marketsbut have yet to develop towards more intensivefood production. As a result, interest in livestockand fish production may remain low even whilehouseholds lack food. In parts of Ghana, theimportance of highly marketable bush meatconstrained interest in small livestock that arecommonly raised but used mainly for ceremoniesand as an emergency reserve (Ruddle, 1996).Project-affected households farming fish tendedto sell their game and eat their own cultured fish.

Clearly the development of aquaculture willbe slower where fish and other aquatic productsare a less important part of traditional diets.Levels of fish consumption are far higher in partsof Africa and Latin America than many areas ofAsia. In Iran and Pakistan for example, traditionalconsumption levels are very low and mainly

limited to consumption of marine fish by coastalcommunities; inland populations in these semi-arid environments traditionally have little accessto freshwater fish. Large-scale irrigation of inlandareas of these countries, such as the Punjab inPakistan, did little to change traditional attitudesand fish consumption levels have remained low.Demand for fish in these countries is growingmore rapidly among urbanized populations thanin rural areas.

Multi-purpose use and benefitsA common phenomenon is the value of pondsbeing recognized by rural people in more holisticterms than planned by promoters workingtowards fixed technical goals. Success inmeeting demand has to be considered in moreholistic terms than fish yields alone. Productionlevels of fish in both household and community-level ponds in Latin America were not sustainedat levels that met the expectations of theirpromoters. Ponds were managed principally as asource of irrigation water for rice and/orvegetables once project support was withdrawn.They were also an important resource forwatering livestock. Evaluating the contribution of

8.7

Farmed stocks contribute to household foodsecurity through:� direct consumption to substitute for declin-

ing wild stocks;

� direct consumption allowing more valuablewild stocks to be marketed off-farm;

� indirectly through sale for cash as less valu-able, small wild fish are available and usedfor subsistence.

What happens to farmed fish inrural Africa, Latin America andAsia?

BOX 8.F


fish alone towards household food security istherefore misleading. Ruddle and Prein (1998),modelling the value of pond water in Ghana,found that water used for vegetables had moreimpact on cash generation and household foodsecurity than the limited output of fish from smallponds. Even significantly increased levels of fishproduction were found to have marginal impacts.Increased interest in ponds during prolongedperiods of drought, principally for the value of thewater stored for vegetable and livestockproduction rather than stocked fish, was commonto smallholders in Malawi (Noble, 1996) andNortheast Thailand (Surintaraseree and Little,1998). The value of the ‘fishpond’ as amultipurpose resource has been accepted in Asiaperhaps longer; water resource projects wereoccasionally ‘disguised’ as fish culture projects inthe 1970s and 1980s to fit with donors interest inaquaculture development. The major purposefrom the outset, however, was rehabilitation ofcommunity water bodies to meet a variety ofneeds. Holistic analyses of the role of pond andricefield-based aquaculture within diversifiedfarming systems elsewhere in Asia point to theirimportance as a multi-use resource, particularlywhere off-farm irrigation is lacking.

BeneficiariesNon-fish farmersEfforts to promote aquaculture have typicallyfocused on a sub-set of individuals withincommunities and, indeed, within households.They have often ignored broader resource issues,and benefits and disadvantages, that result forthe wider community. Clearly access to, andexploitation of, community water and nutrientresources by some individuals can impoverishothers. However, non-fish producers may benefitfrom aquaculture through improved availabilityand lower priced fish.

Reduced access to land and water by poorerpeople as it is appropriated for use for aquacultureby richer people appears to be a significant

emerging problem in areas of resource scarcitywhere, incidentally, conditions are often suitablefor aquaculture. Use of low-lying wetland areas(dambos) in Luapula, Zambia for fish pondconstruction stimulated a scramble for resources inwhich other uses and users were excluded(Harrison et al., 1994). The same is clearly animpact of successful aquaculture adoption inBangladesh where drainage of common propertywater bodies for privately-owned ponds andencroachment by rice growers is reducing theavailability of small indigenous species of particularimportance to the poor (Thilsted et al., 1997).

Intra-householdThe focus on extension of aquaculturetechnology to male head-of-households has beenquestioned for a variety of reasons in Africa, LatinAmerica and Asia. Again, there is probably asmuch variation within as between thesecontinents, with respect to how decisions ofresources are used and benefits distributed.Unequal opportunities within the household touse and inherit land (and ponds), obtain credit,market or distribute products and accessinformation occur widely. Gender-blind planning,with negative consequences, has typically beenthe norm as has a failure to understand other ageand power relationships within and betweenhouseholds. Intra-household relationships maybe particularly important where food is scarce.Insufficient staple and complementary cropproduction underlying the malnutrition ofresource-poor households farming fish in Ghanaare exacerbated by cultural factors governingintra-family food consumption.

Community and group-based developmentPromoting aquaculture to groups of farmers hasbeen tried with varying success in all threeregions. Sometimes groups are used as theextension focus for either individual household-based production, or for a community-basedactivity. Efforts to ensure equitable development ofaquatic resources have often been an incentive topromote community or group-based aquaculture.A community approach may also result from a lack

8.8


of potential for the targeted group to haveindividual ponds, or the fact that the waterresource already exists but is underutilized. Ruralcommunities are often situated around naturalwater bodies. In addition to them being a source ofwater, they also typically act as drainage basins forlivestock and other wastes, and are often highlyproductive as a result. Sometimes, often as part ofefforts to integrate rural development, livestockcomponents have been actively promoted, such asin the Village Fish Pond Project in NortheastThailand (Box 8.G).

A range of management issues reduceopportunities to intensify production, althoughprovision of alternative domestic water supplyovercomes some of the problems. Manysimilarities can be found with the situation inPanama (Box 8.H) where efforts to promote theuse of community ponds for fish production haveresulted in multiple uses and products beingdeveloped, but fish yields well below thosetechnically possible.

Community approaches to extension haveproved successful in Asia. In Bangladesh suchare the social constraints to targetingaquaculture development to the poorest in thecommunity, a whole village approach hasachieved good results. Such communitydevelopment is not only efficient in terms ofextension effort, but the inclusive approach alsoensures that social tensions are notexacerbated between wealthier people andpoorer groups. The participatory techniquesthat support the approach have also allowedsocial constraints, such as participation bywomen in pond activities, to be overcome byencouraging peer support and evaluation(NFEP, 2000).

The relatively high retention of livestockintegrated within community pond systems inPanama, albeit on a more extensive and lessconsistent level than envisaged by the projectplanners, is noteworthy. External factors (roads,feed availability and marketing opportunities)

� The nature of current interaction with live-stock. Conflicts arising through access oflarge ruminants to wallow in communityponds are resolvable through access restric-tions.

� Spatial location of community ponds and set-tlement pattern of the community1.

� Traditional management and feeding systemse.g. free-range ducks, liable to theft of eggsand animals led farmers to pen ducks in thehomestead plot, reducing access of ducks towater body once intensified1.

� Use of pig manure allowed the benefits ofintegration to be appreciated before pigswere relocated to household-managed ponds.Many households abandoned pig productionafter initial subsidies were withdrawn1.

� Requirements for an alternative water sourcefor domestic purposes were resolved through

provision of shallow well nearby2.

� The level of regular stock management andharvest.

� Active village committees, representative ofthe community and reactive to their needs arecritical. Benefits need to be seen to be accord-ed to the community as a whole, rather thanbenefit a small elite.

� Continued access of the poorest to non-fishresources e.g. aquatic plants, crustaceans,amphibians and snails4.

� Management of stocked community pondsand reduced fishing effort resulted in anincrease in the role of the pond as a refuge forwild fish species with potentially beneficialeffects on seasonal rice field fish yields5.

Sources: 1AASP (1996); 2Garaway (1995); 3Garaway (1999); 4Lorenzen et al. (1998a); 5Lorenzen et al. (1998b)

Factors affecting the success of integrated livestock aquaculture in community managed water bodies in Northeast Thailand and Lao PDR

BOX 8.G


had become more positive since projectinception. There is also evidence that access tobenefits had become more concentrated towardssingle owners and related kin. The focus on usingponds for rice production suggest that this was ade facto ‘privatization’ of the communityresource (Lovshin et al., 1986).

The timing of interest in intensified fishproduction is often critical. An expected futureshortage of fish stimulated attempts at low inputcommunity aquaculture in Nigeria, but therelatively high residual wild fish availability and apoor understanding of the social issuesundermined the attempt (Thomas, 1994). Theconstraints identified to (Box 8.I) have alsooccurred in Asia with similar agro-ecological andsocial environments.

Comparing the regionsA range of factors can be identified that haveinfluenced the belief that rural aquaculture hasmet with more success in Asia than either Africaor Latin America (Box 8.J). The analysis suggeststhat a generally higher population density in Asiaand greater relative reliance on aquatic food inmost rice-dominated agroecologies explainsmuch of this dichotomy, but that aquacultureintegrated within the farming system can oftenbe relevant to the needs of poor rural people. Thebasic constraints to adoption of aquaculture bythis group, and its integration with livestock, aresimilar.

8.9

In Panama the promotion of aquaculture amongorganized groups of poor farmers (campesinos)was supported through training, assistance inpond excavation and setting up integratedlivestock and crop production over a two yearperiod

Early evaluations found that:� groups worked best when the community was

not highly stratified;

� groups in communities with relatively fewpublic and private commercial services;

� groups with their leadership drawn from with-in, rather than elites, were most sustainable.

After a period of 14 years, an evaluation foundthat adoption had not been sustained at the level,or in the manner, planned. Fish production levelshad declined and direct nutritional benefits fromfish judged minor since the time of the project.However, the community had generally adaptedponds to produce rice, which were oftenintegrated with fish culture, and continued to usethem as a focus for livestock and fruit production.

Unfortunately, an evaluation of the benefits fromthese activities was not presented but it seemslikely that the current utilization was meetingsome needs of the communities involved.

A range of social, economic and technical factorswere identified to explain this, all of which couldbe drawn from projects in Asia: � lack of timely availability of fingerlings hin-

dered the efficient use of ponds;

� groups found it difficult to manage livestock,especially financing inputs. Livestock num-bers and management were ‘sub-optimal’ butthis was the only major source of nutrientsentering the ponds in community projects;

� poor site selection, especially when waterretention was poor and culture seasonal;

� out-migration of the young, reducing labouravailability e.g. men leaving for constructionindustry;

� difficulties in managing loans;

� land ownership issues of community projects.

Source: Lovshin et al. (2000)

Promoting community-level aquaculture in Panama

BOX 8.H


Situated in the Hadejia-Nguru wetlands ofNorthern Nigeria, a community approach toaquaculture was promoted in a village of 1200people. Although fish production per hectare was171 percent greater in managed compared tounmanaged ponds, and returns to labour werefavourable to alternatives, the project was notsustained:� the technology was ‘simple’ i.e. wild seed

surplus to catches of food fish stocked inponds fertilized with cow manure;

� poor levels of community participation wererelated to:

�a lack of any custom of community fishing,and

�inappropriate management structure,despite being based on indigenousinstitutions and maintaining linkages withState organizations.

� poor levels of education (literacy and numer-acy) prevented the community monitoringthe project effectively;

� fishers were reluctant to contribute even lowvalue fingerlings because they were not con-vinced of a return;

� change in how the fish were harvested anddisposed of conflicted with traditional prac-tices;

� reduced rights of access to certain groupswhich increased social tensions between eth-nic groups;

� aquaculture didn’t meet the needs of particu-larly the poorer people who would rathercatch 1 kg of wild fish than obtain more fishlater.

Source: Thomas (1994)

A failed attempt at community aquaculture in Nigeria

BOX 8.I

1. Greater dominance of ‘projects’ in evaluationof success, criteria for success and farmersattitudes to inputs. Greater importance in the‘culture of development’ to adoption.

2. Less availability of markets and market chan-nels for inputs such as cheap, synthetic netmaterials.

3. Less long term consistent attempts to pro-mote aquaculture by Government and NGOs.

4. Less core resources developed in terms ofearly adopters that can support new entrants,although where they have, suggestive of a

similar role to that in Asia. This may be relat-ed to (3) and a lack of traditional wild seedcollection and use.

5. Lower population densities and need for cul-tured fish and on-farm irrigation also reduceseffectiveness of change agents in aquacultureand other new activities.

6. Less traditional importance of freshwater fishin the diet. Relatively smaller proportion ofthe population in Africa and Latin Americawhere fish and aquatic products constitute amajor proportion of dietary animal protein.

Factors influencing the relatively lower success of rural aquaculture inAfrica and Latin America than Asia

BOX 8.J

CHAPTER 9 • FUTURE DIRECTIONS IN LIVESTOCK-FISH INTEGRATION 145

9

Future Directions inLivestock-fish Integration

The first questions addressed in this final Chapter relate to the

opportunities and major constraints facing the continued development of intensive

livestock and fish production. The factors stimulating these trends are examined and

critically analyzed and the case made for novel or renewed closer integration. The

relative opportunities for livestock waste use through aquaculture are then examined

and contrasted with alternatives such as their value for crop production and energy

generation. Trends in food consumption and water use are reexamined, and

opportunities and threats to integrated livestock-fish production considered.

Opportunities for aquaculture and livestockwithin nutrient-poor, small-holder systems arethen reviewed given our analysis in earlierChapters and new approaches to multipurposewater use.

Demand and globalizationGlobal trading networks are increasinglychallenging the concept of self-sufficiency andconsumption norms. Much of the increase indemand for livestock and fish products isexpected in LDCs, both in rural and urban areas.

Although rural communities in LDCs areexpected to grow further before stabilizing, full-time farming in many agro-environments is likelyto decline. Demand for both livestock and fishproducts can therefore be expected to increasein rural as well as in urban and periurbanenvironments where demand will climb evenmore swiftly.

Applying conventional sources of feeds andproduction systems is expected to allowresponse to these demands in the short-term,largely through increases in grain and proteinfeed crops in Brazil and the USA and a few otherfood surplus countries. In the medium-term,growth in demand may stagnate in countries

9.1


with limited reserves of foreign currency, largepopulations and small capacity to increase cropproduction further. Countries such as Japan,Korea and Malaysia that import large quantitiesof feedstuffs will be particularly sensitive toglobal shortfalls in livestock feed ingredients(Farrell, 1996).

Commercial livestock production willincreasingly be drawn to areas of relativeadvantage, especially those for processedproducts, often to areas within reach of ports forshipments of feed, or close to the areas where thefeed is produced. Stringent environmentalregulations and shortages of high quality water,in contrast, will also restrict intensiveaquaculture. This will draw internationalinvestors towards less-densely populated regionsand could impact relatively severely on thenatural environment.

Feed resourcesThe major single limiting factor to increasedlivestock and fish production will be availabilityof feed. Competition for feed occurs at both thelocal level, usually for grain by-products such asbrans and oil cakes, as well as the national andinternational level for concentrates of cereals,pulses and animal products (fish and meatmeals). Fish meals and oils, being dependent onwild stocks, are particularly limiting for feedlotlivestock and feedlot fish, particularly salmonidsin colder countries and shrimp in the tropics.

Increases in the real price of concentrates areexpected as globalization of world trade occurs,wild fish-based products become relativelyscarcer and demand for livestock products soar inindustrializing parts of the world. This will favourthe most efficient users of concentrates in bothlivestock and fish production sectors andsubstitution of high cost ingredients; indeed thepercentage of fishmeal in livestock feeds hasfallen markedly in recent years.

Estimating the quantity of feed ingredientsrequired in the future depends on how manyanimals are housed intensively, and how many

remain extensively managed (Farrell, 1996).Currently a large proportion of livestock areraised extensively in developing countriesalthough the overall trend is rapidly towardsintensification.

Improving feed efficiency is a major challengeto animal and fish nutritionists, particularly forintensively raised monogastric livestock and fish.Increased feeding efficiency has already allowedthe amount of livestock production to increasefaster than demand for concentrates over the lastdecade. If the productivity gap can be closedbetween OECD countries and China, and otherdeveloping countries with rapidly growingdemand for pig and poultry products, greaterproduction can be expected without largeincreases in demand for concentrates (de Haan et al., 1997).

Broader definitions of efficiency may bemore relevant in the future. Feeding efficiency,which is typically expressed as a FCR, giveslittle information on the quality of the feed orhow feed is used within a broader farmingsystem. Scavenging animals fed asupplementary feed produced on-farm, usuallygrains or grain products, will have poorerconventional conversion efficiencies thanintensively-raised animals fed compoundeddiets. Wastes derived will also generally be oflower value for aquaculture. However cashoutlays may be negligible and farmers, by usinglow cost grains in this way, add value to theirfarming output in an ‘efficient’ manner. Theprospects for more use of concentrates and role of ‘improved’ strains by small-holders isconsidered later.

Grains and grain products are also the largestcomponent of compounded livestock feeds,accounting for 70,75 and 65 percent of modernpig, broiler and layer diets, respectively (Farrell,1996). Concentrates, typically comprisingsoybean and fish meals together with a range ofhigher cost additives (vitamins and minerals) isadded to meet the exacting nutritional needs ofbreeds selected for their performance on suchfeeds. Feed conversion efficiencies are high butmany factors, such as access to concentrates andmarkets and pricing of inputs and products, limitsmall-holder involvement.

9.2

The overall efficiency of both traditional andmodern feeds and strains can be improvedthrough their integration with fish. If overallproduction per tonne of feed is considered,integration can be seen to dramatically improveoverall efficiency. Similar gains are possible whenfeedlot fish culture is integrated with semi-intensive culture of carps and tilapias.

Development away from conventional, grain-based livestock and fish production systems hasbeen identified as a need for the humid and sub-humid tropics where cereal deficits are common.Alternatives include greater use of feedstraditionally used in some areas e.g. sweet potatoand cassava, and development of unconventionalfeeds e.g. sugar cane, green pulse fodders, sugarpalm (Preston, 1990).

Intensification not concentrationSustainable recycling of wastes produced byindustrial livestock systems must be attractive,both financially and environmentally. Integrationof aquaculture into such systems can beattractive; current linkages between better-offperi-urban livestock farmers, with little land and alot of waste, selling waste to farmers specializingon horticulture or fish, already exist in parts ofAsia. Good infrastructure (especially roads) andan enabling environment for the trading ofinputs, products and by-products are necessaryto make such options viable.

The relatively high value of nutrients and fewtechnical alternatives for waste disposal haveprobably encouraged the development of thesesystems where they are important. However, inmany areas of high livestock concentration,nutrient surpluses are often common. Recyling onthe limited land areas within easy reach ofproducers can result in excessive loading,leaching and pollution of surface water. Highwater content of livestock wastes and transportcosts limit the distances to which they can beused. Mineral fertilizers are often cheaper andeasier to use.

The factors that have encouraged livestockproduction to become concentrated need policychanges to stimulate more rationale use oflivestock wastes (Box 9.A). Improved overallefficiency of food production should be the aim,with an emphasis on reducing waste outputs ofthe whole system. The growth of industrialsystems has been greatly stimulated by policydistortions in Western Europe, exacerbating therelative advantage of livestock producers thatconcentrate in the Netherlands, Brittany andother areas of Northwest Europe. In Singapore,the negative impacts of concentrated, intensivepig production has led to its abandonment (Box9.B). These incentives may be unaffordable indeveloping countries, but poorer infrastructureand access to markets encourage livestockproducers to concentrate in peri-urban areasresulting in similar concentrations of livestockoperations and negative impacts. The samephenomenon has occurred in intensiveaquaculture where the carrying capacity of thelocal environment has been exceeded such as thesites of intensive cage culture in reservoirs inWest Java. The relative sensitivity of mostcultured aquatic animals to changes in theirenvironment may be an important factor in self-regulation but often not before long-term

9.3


� Reduce policy distortions such as low importtariffs on cereal substitutes and high domes-tic prices for beef and milk in Europe(Steinfeld et al., 1997).

� Tax effluents from livestock and fish produc-tion.

� Classification and zoning of watersheds withproduction ceilings linked to levels and effi-ciency of on-site waste reuse.

� Reduction in regional inequalities in infra-structure development.

� Effective information dissemination to dis-advantaged areas.

Possible policies to discourageconcentration of intensive livestock and fish production

BOX 9.A


environmental and social damage has occurred.A range of measures may be useful to intensifylivestock and fish production (Table 9.1) withoutspatial concentration.

Peri-urban integrationMany forces are stimulating more technicallyadvanced integration of food production.Increasingly, both public opinion and safety,concern for animal welfare and zero pollution

must be satisfied. In the western world, pollutionprevention and alleviation will drive both publicand private investment in food production intothe foreseeable future and zero pollution willbecome the target. In land-rich, warmercountries lower technology solutions willcontinue to develop, subject to stricter adherenceto safety issues. Global trade will increasinglyreduce the current differentials between hygienerequirements in LDCs and the developedcountries and, meeting the media-fueled,consumer expectations will be critical todevelopment of sustainable food production of alltypes.

9.4

Measures to intensify livestock and fish production without spatial concentration

Problem Appropriate measures

Increased urban demand leads to concentration and • Discourage mega-urbanization; encourage provincial urban growthintensification of livestock production • Limit size of livestock holdings

• Encourage agribusiness to target small-scale operations with appropriate concentrate formulations, germplasm and veterinary support

In areas of high livestock-fish densities, high pollution • Introduction of pollution levies and regulationsoccurs

Concentration of livestock/aquaculture due to availability • Improve infrastructure, allow markets for feeds to operate competitivelyof feed • Identify and develop alternative types of livestock feed

• Encourage local processing of crops and crop products

Concentration of livestock/aquaculture due to restricted • Improve infrastructure access to markets • Encourage local processing industries

Technology developed for industrial production only • Target small-holders for R&D efforts

• Adopt farmer-first paradigm by extension services

• Ensure free competition in markets for inputs and outputsDichotomy of industrial and back-yard systems • Increase availability of appropriate information to small-holder

livestock farmers

TABLE 9.1


In developed countries, biological processeshave in some cases been superseded by use ofindustrial processes but the support costs maynot be sustainable in the long term. Increasinglya return to, or combination with, microbial, fungalor invertebrate treatment processes for wastes, oras part of the production process, look likely.

The development of export-led livestockproduction, in which processed by-products remainin-country and are used to support fish culture, hasobvious merits. This practice leads to efficientrecycling of wastes at source, both production andprocessing, whilst generating high-value, low-costanimal protein in addition to foreign revenue.

Geographical rangeUsing fish culture as a component of broaderfood production systems has most potential inthe tropics where temperatures remainelevated and stable year-round. However,wastes have been used traditionally for aquaticproduction in both the sub-tropics andtemperate zones. The lower temperatureregimes of tropical highland areas such asRwanda, are also known to reduce aquaticproductivity (Molnar et al., 1996).

Trends in land and environmental planningsuggest opportunities exist for aquaculture tobe more central to waste disposal in the future.Variations in ambient temperatures through theyear is an important design criterion forbiological waste treatment of any type. Theresidence times of wastewater passing throughstabilization pond systems in temperate zonesare based on changes in seasonal efficiency.Poorly designed systems result in seasonaloverloading and fish die-off, such as occurred inpoultry-fish systems in Hong Kong (Sin, 1980).Integration of large pig production units andfish culture has occurred in Hungary andtreatment of wastewater has been traditional inEurope and subtropical parts of Asia (Edwards,1992). Ensuring optimal loading rates of organicwaste, be they of animal or human origin, mayrequire pre-treatment and storage capacity inmost cases to ensure wastes are usedefficiently.

The use of livestock wastes must be viewedwithin the context of further increases inorganic waste production of all types and thelikelihood of more stringent control of dumping,land fill and other methods of disposal. Anincreased role for artificial wetlands withinurban and peri-urban landscapes wouldenhance flood control, wildlife conservation andwastewaster treatment. Integration of fishproduction is a traditional feature of suchsystems in some Asian cities. Incorporation ofaquaculture within broader water andwastewater treatment and storage has becomea major part of Israeli settlement patterns wherewater conservation has made the use ofwastewater for secondary irrigation a necessity.

Impacts

• Stimulate equitable growth and development; reduce urban:ruralinequalitities

• Increase in part-time farming

• Intensification and increased efficiency without drastic declines in spread of livestock operations

• Increased opportunities for cost-effective integration within wider farming systems

• Reduced likelihood of intensification of fish culture

• Reduced need for reliance on inorganic fertilization

• Competitiveness of small-holder operations maintained

• Adoption of no-effluent systems and linkages with nutrient-poor, horticulture/semi-intensive fish production

• Development of intensive, integrated fish culture based on tolerantspecies

• Increased employment opportunities

• Diversify farming systems, land use by using unconventional plant and other feed materials


• Improved opportunities for integration in more diversified food production systems


• Small-holders improve livelihoods by improving food production systems

• Small-holders enhance livelihoods by improving food production systems


Use of animal wastes for other purposesThe major problem of animal waste disposal hasstimulated research and development indeveloped countries towards alternativemethods. Recycling by spreading on arable landhas many constraints and has resulted insignificant damage to groundwater resourcesand natural aquatic and wetland ecosystems.Odour and the leaching of nitrates and otherpollutants into groundwater has spurredlegislation in Europe and in Singapore hastenedthe phasing out of intensive livestock production(Box 9.B).

A major problem is the sheer concentration ofanimal wastes, typically collected and stored asslurry, which is expensive to transport and treat.Most strategies require considerable energy todry the waste. Separation and composting ofmanure solids and its use for high valuehorticultural container medium is possible

(Inbar et al.,1993) but given the amounts havelimited impact (Box 9.C).

On-site processing (drying, composting andfermentation) are options but are unlikely to becost effective if low value soil conditioners aloneare produced. However, the use of fresh manureto produce live feeds, primarily for fish and also alow-moisture, compost-like material forhorticultural use has proved commercially viable(Nuov et al., 1995). Farm mortalities andprocessing wastes are other major by-products ofintensive livestock production that have oftenbeen disposed of in landfills or incineration,although local composting has been recom-mended by some. Rendering to meat meals hasbeen a conventional approach for such productsbut is now subject to criticism by bothconsumers and legislators following the BSEcrisis. Re-feeding of poultry litter and otherwastes has been a standard practice in someareas (Chapman, 1994).

� High demand for pork in Singapore becausethe Chinese ethnic majority (78 percent) has adietary tradition of consuming pork and it isnow an indispensable part of their diet. Annualconsumption levels are 35 kg. caput-1.

� A total population of 2.5 million people livesin a total land area of 620 km2.

� Over three decades the standing pig popula-tion increased from 400 000 animals raisedmainly in small units scattered through ruralareas (1960) to 750 000 before relocation to asingle 650 ha site (1980). The Governmentthen decided to phase out pig productioncompletely by 1990.

� Incompatibility with urban growth: Locationin and discharge of waste waters into catch-ment areas used for municipal water supply,disposal of solid wastes and malodours.

� Recovery and use of pig waste was hampered

by the need to use water to remove wastesand cool pigs and led to dilute slurries (1 per-cent solids) that were difficult to handle anduse without large areas of land. The predomi-nantly muslim workforce also constrainedhandling of pig manure. Attempts to reducewater use failed when pig performance suf-fered under high ambient temperatures.

� Local demand for fresh rather than frozenmeat made Singapore produced pork compet-itive with imports, even when pollution con-trol measures were enforced, that addedaround 4 percent to production costs.

� Conventional, semi-intensive fish productionwould have required 7 500 ha of land to treatthe wastes of the Singapore herd. Intensifica-tion following methods by Nuov et al. 1995,would have reduced this to 10 percent of thisfigure.

Source: Taiganides (1992)

Singapore phases out pig production

BOX 9.B

Marketability of fish produced inlivestock-fish systemsThe trend for rising fish consumption inindustrial economies, especially in countries withtraditionally low consumption, is gainingmomentum. Increasing affluence and thedemonstrated health benefits of eating fishregularly appear to be important underlyingreasons for this trend. The health benefits ofpolyunsaturated fatty acids contained intemperate, usually marine fish have also nowbeen shown to occur in warm water carps(Steffens and Wirth, 1997).

The ecological benefits of eating such fishfeeding low in the food chain rather thancarnivorous species have yet to become a majormarketing angle, but will undoubtedly become an

issue. Currently, those marketing farmed fishmake association with natural fish stocks andpristine environments. A key relative advantageof fish is that it is one of the few foods stillavailable from natural environments; thosemarketing fish focus on the ‘clean’ and ‘natural’credentials of their product. Sites are identifiedfor their unpolluted nature, even though intensiveaquaculture typically results in significantdeclines in downstream water quality. There aredangers, therefore, in any association of farmedfish with ‘waste’ of any type, especially in thelight of increased consumer sensitivity to foodscares in developed countries. Practically, aperiod of intensive fattening of waste-fed fish in aseparate system should satisfy the need forensuring consistent quality and for distancingthe waste and the product eaten by theconsumer. Another approach is to process freshwastes through intermediate live feed organismsbefore feeding to fish consumed by people(Edwards, 1990). Using unprocessed livestockwaste to produce fish up until the time ofmarketing may be unacceptable for consumersunaware of the realities of food productiongenerally. Ironically, the rapid rise in demand for‘organic’ products in industrialized countriesmay signal a change in attitudes from which fishfarmed in organically fertilized, aquatic pasturesmay benefit.

Clearly, if waste-fed fish are to be acceptableto sophisticated urban consumers, a range ofefforts will be required. HACCP principles needto be applied to reduce risks of pathogen transferat all stages of production and processing.Different approaches to lengthening the foodchain, rigorous monitoring of quality and a focuson the ‘organic’ qualities of fish produced will allsupport marketing of fish produced in this way.

Rural integrationA variety of factors affect opportunities for moreintegration of livestock and aquaculture in ruralareas of developing countries. These relate todemography, as predominately rural societies

9.5


� Efforts should be made to improve efficien-cy of feed in livestock-fish systems. Separ-ation of waste feed from faecal and beddingwaste is desirable in intensively raised live-stock. Waste feed has a high direct feedingvalue for fish in semi-intensive systems.

� Solid wastes are valuable for soil-based agriculture. Faecal and bedding waste usedas arable crop inputs increase nutrientretention capacity (cation exchange capaci-ty) and physical condition of soils throughimproved water-holding capacity and soilstructure.

� Solid waste, especially those with high C:Nratio, increase the demand for dissolvedoxygen through high COD.

� Wastes with a high moisture content areexpensive to transport.

� Rapid transfer of liquid wastes to pond sys-tems reduces nutrient losses.

Separation of solid and liquidwaste fractions improves the efficiency of livestock waste use in farming systems

BOX 9.C

urbanize and change their expectations and thenature of demand for food. Policies that promotelivestock and aquaculture, especially with regardto the importation, production and marketing offeeds and breeds, are critical. Intensification ofsmall-holders’ livestock through developingalternative feeding strategies based on locally-produced and purchased feeds, is alsoconsidered.

The availability of nutrients in rural areas is amajor constraint to productivities of bothterrestrial and aquatic systems. The role ofextensive production methods for nutrient-poorsituations is considered. A further issue ofimportance is the role of on-farm irrigation inagricultural development and how ponds delivermost benefits as a multipurpose resource.

Changing Demography and demandRural migration, while reducing labour for raisinglivestock and fish, also reduces demand for small-scale, locally produced livestock and fish. Thiscan be compounded if improved roads and otherinfrastructure favours import of low-costcompeting products into rural areas, furtherundermining demand for locally produced food.There is a tendency for large producers tosqueeze small farmers in this way despite localpoultry being considered superior to intensivelyfarmed birds in most of Asia. Improvedinfrastructure can, however, allow import ofproductivity-enhancing inputs and access tourban markets (Box 9.D). This is particularlyimportant as the agricultural work force ages andlabour efficiency becomes critical for innovationsto be sustained. Government policy to encouragerural livelihood options that include diversifiedagricultural, service and industrial developmentis required.

Intensification using modern breedsand feedsModern breeds require balanced, high-valuenutrition that can be produced with strategicimports even in resource-poor areas. Ifconcentrates appropriate for blending with localgrains and by-products are available, smallholders can produce pigs and poultry veryefficiently and benefit from the valuable nutrientsfor fish culture. One analysis in NortheastThailand indicated that use of concentrates tocomplement local rice bran and cassava as a pigfeed could increase herd size by a factor of 8 andthe amount of fish by ten (Little andSatapornvanit, 1996). Government policy toactively encourage agribusiness to focus on theneeds of small-holders by improving the


Improved infrastructure, particularly roadnetworks and availability of feed concentrates,has improved markedly over the last twodecades in rural Northeast Thailand. This hasraised opportunities for small-holders tointensify both livestock and fish production.Previous attempts to promote duck eggproduction integrated with backyard fishproduction had failed for a variety of reasons(Box 7.Q). A recent Department of Fisheriesinitiative to promote egg-duck integration withcommunity fish production appeared to havepotential as duck egg production was nowviable even in remote areas. However, inpractice small-scale production integrated withindividually owned, or community fishponds,remained constrained by a variety of factors.Labour constraints forced holding the ducksaround the homestead rather than over thewater body and encouraged flocks to becomelarger. Wealthier people, usually women whocould afford the regular cash investment,tended to specialize in duck egg production.Government programs purchasing duck eggsfor children’s school meals stimulated regulardemand in the village but competition withcheaper chicken eggs distributed throughnetworks of middlemen reduced profit margins.Many of these eggs were derived from layeroperations, usually located in irrigated areas ofthe region, which were integrated with pondfish culture (Engle and Skladany, 1992).

Changing opportunities for smallholders to integrate egg-duck and fish production

BOX 9.D


availability to them of modern strains, feeds andveterinary services to them in rural areas isrequired. Decentralized livestock production andmarketing will also benefit local consumers andservice providers.

Alternative approaches to intensification-novel feed and traditional breedsIn some situations local breeds and feeds havebeen found superior to those introduced. Often ahybrid approach, in which local and introducedstrains are hybridized and local feedssupplemented with improved varieties andinputs, is required on a practical level.

Understanding the nature of constrainingfactors is also important. A lack of dietary energy,rather than protein, has been found to limit theproductivity of scavenging poultry and can bestbe improved through use of locally availablesupplements (Men, 1996). In contrast, protein is amajor constraint to increasing productivity ofpenned local and hybrid pigs in Viet Nam. Lowinput strategies for monogastrics make use ofboth a natural ability to scavenge andomnivorous tendencies. Pigs utilize micro-organisms in the caecum and colon to digestmaterials unhydrolysed in the stomach and smallintestine (Livingstone and Fowler, 1984). Diets ofbreeding animals can include a high proportion

Levels of input as well as output determine theefficency of production, by definition. Whereasthe energy requirement of an intensively-rearedWhite Leghorn is 300-320 kcal ME. bird-1 day-1, asmaller native scavenging bird requires aminimum of 286 kcal ME. bird-1 day-1, althoughlower levels of egg production are supported.

But, if under an intensive system 240 eggs.bird-1 can be produced but the total cost of inputsequals 220 eggs, the net production is only 20eggs. bird-1. In a scavenging system around 40eggs. bird-1 can be produced without anyadditional feed costs, representing a net productionof 40 eggs. bird-1. Supplements used strategicallymay improve on this level of efficiency.� Strategic supplementation needs to under-

stand seasonality and local differences in foodavailable through scavenging (especially ener-gy, crude protein, calcium and phosphorous).Significant differences were found in poultryfrom villages at different altitudes in theCentral Highlands of Ethiopia.

� In Ethiopia it was concluded that energy-richsupplements should be given year-round, andprotein supplements in the dry season, whenavailability of worms and young plant materi-al was low.

Concentrates that increased protein up to100g protein. pig-1 day-1 increased live weightgain, cost effectively, by 83 percent (Nguyen,1996). Even small amounts of commerciallyproduced concentrates are often unavailable orprohibitively expensive in rural locations,however. Small fish regularly harvested as a by-product from a pond receiving livestock andother wastes could be used as a strategic feedsupplement to enhance the productivity oflivestock (Box 9.F). Alternatively, seasonalsurpluses of wild and culture fish can be sun-dried or fermented for use throughout the year.The nutritional value of such approaches hasbeen confirmed by trials in which waste-fedtilapia were tested as carnivorous fish andlivestock feeds. The practice of using the fishpond as a feed source for penned livestock isalready common in Northern Viet Nam whereaquatic weeds are harvested and fed to pigs. Themain issue is the likelihood that even small fishhave a higher value for direct human food thanthe extra benefits to pig production from usingthem as a supplement. A simple analysis suggeststhat this strategy is unlikely to be attractiveexcept where fish have low value.

Assessing efficiency of traditional, upgraded and modern livestock systems

BOX 9.E


of bulky feeds if complemented by small amountsof cereal/concentrates. Conversion efficiencies oftraditional strains of animals on low-inputsystems are poorer than modern breeds fedformulated rations, but environmental impactsand support costs are lower. When feeds are notgiven, or given in small quantities, suchmeasures are not meaningful and ‘efficiency’needs to be reassessed (Box 9.E). Very significantimprovements in productivity can be attainedusing strategic feeding of locally availablesupplementary feeds to traditional varieties ofscavenging poultry (Box 9.F).

Extensification - use periphytonChronic under-fertilization of ponds is a majorproblem in resource-poor farms throughout LDCs.Lack of knowledge of the possible benefits, or awish to avoid eutrophication of stored water for avariety of purposes, may explain this‘mismanagement’. More often a lack of availablenutrients means that production is sub-optimal.

Where land holdings and ponds are small andagriculture is intensive, efforts should be made tooptimize plankton-based fish production oftenusing inorganic fertilizer. In situations whereponds are larger and nutrient requirements tooptimize autotrophic-based production are high,more strategic use of nutrients may be advisable.Research in Bangladesh has found thatsubstrates placed in relatively infertile ponds toincrease periphyton can almost doubleproduction of fish (Wahab et al., 1999). A longestablished tradition in West Africa of usingsubstrate to attract wild fish evolved into acajadasystems in which periphyton growing on thesubstrate also becomes a food source for stockedfish.

A constraint to the wider adoption of thesesystems is the opportunity cost of suitablebiomass. Wood and woody waste are in demandfor fuel and other purposes in most LDCs. Inten-sification of ruminant livestock that involvesgrowing leguminous multipurpose trees for

Assume: one pig raised from weaner to finisher over150 days requires an extra 100 g protein. pig-1

day-1 to improve productivity and returns1.Assume: fresh, small-sized tilapia contain 62percent crude protein on a DM basis, fresh tilapia

are 76.8 percent moisture. Then, 696 g fresh fish.day-1 are required, or 105 kg over 150 days. Thesize of pond required to produce this amountwould depend on the yield

Feeding pigs on small fish

BOX 9.F

Fresh fish produced (kg) to support a 150 day pig production cycle in pondsof different sizes and yields.

Pond Area (ha)

0.01 0.02 0.05 0.1 0.15 0.2 0.30.5 2 4 10 20 30 40 601.0 4 8 20 40 60 80 1201.5 6 12 30 60 90 120 1802.0 8 16 40 80 120 160 2402.5 10 20 50 100 150 200 3003.0 12 24 60 120 180 240 3603.5 14 28 80 140 220 280 4204.0 16 32 100 160 260 320 480

Fish Yield(t ha-1 y-1)

Source: 1Nguyen (1996)


fodder and fuel as borders, or on marginal land, isone strategy to increase both the availability ofwoody substrate and quality livestock feed.

A further linkage between periphyton-basedsystems and livestock would be to soak substratein livestock urine to increase periphyton growthand, subsequently, fish production.

Water resourcesThe universal value of perennial water on-farm toenhance productivity and reduce drought- andflood-related loss has been greatlyunderestimated by institutions promoting fishculture. Water bodies, both community andhousehold, have traditionally served a variety offunctions in rural areas including livestock andfish production (Table 9.2). Maintaining orenhancing the multiple uses of water bodies maybe the cornerstone of wider adoption of fishproduction by poorer people. Water bodies,whether ponds, weirs or small dams withinwatersheds, have important roles in nutrient

conservation and concentration in addition totheir primary function of water storage fordownstream irrigation.

Irrigation of high-value vegetable and fruitcrops planted around perennial ponds, and assuccessive plantings in the exposed sediments ofseasonal ponds, have been shown to have greaterimpacts on household food security and incomethan the fish produced. In a range of models ofpond-based fish and vegetable production inGhana, fish yielded only between 1-2 percent ofon-farm income (Prein and Ofori, 1996). Unsurpri-singly farmers, especially women responsible forboth production and marketing of such ‘home-stead’ crops, often concentrate resources forvegetable production rather than optimisingoutputs of fish.

The relative size of the pond given the overallland holding, suitable conditions for pondconstruction, and availability of inputs (and fishyields), interact to determine the optimum for anygiven conditions. In Northeast Thailand

Schema of the major interactions between the various subsystems in a crop/livestock-fish integrated farming system

FIGURE 25

Human excreta

Water

Mud

Fishpond Excreta Livestock Crops

Source: Edwards (1993)


construction of ponds to alleviate watershortages in rainfed areas has been widelypromoted through subsidised construction andextension. Linear programming has been used toinvestigate optimal resource use and it wasfound that earthen ponds of 1 000 m2 can produceover 20 percent of farm income on mixed farms in which vegetables, rice and cassava are theother main crops (Setboonsarng and Edwards,1998).

PotentialTrends in food production and consumptionwithin Asia point to large inequalities betweenand within countries. High-income countries inEast and Southeast Asia are consuming moremeat and fish in absolute terms and as aproportion of the total diet than before. Incontrast, rural livelihoods in poorer countries,particularly among marginalized people, may bedeteriorating in terms of diet and overall welfare.Whereas small-scale farms in South andSoutheast Asia raising livestock and fish aretypically crop-dominated and nutrient-poor,

‘industrial’ commercial livestock farms arenutrient-rich and may have significantenvironmental impacts if wastes are not recycled.Traditional livestock systems may not producewastes in either enough quantity or of suitablequality to sustain current grain crops. The use ofthese wastes for aquaculture may therefore havenegative impacts elsewhere in the farmingsystems. In contrast, modern systems tend to beconcentrated in peri-urban areas where use ofwastes to fertilize either field crops or fishpondsis impractical.

Under certain conditions a fishpond couldbecome the focus for diversification of small-scale farms in developing countries. Ponds inwhich fish are stocked can be used for thestrategic irrigation of both crops and livestock.Integrated water use for agricultural anddomestic purposes is often the primary incentivefor incorporation of fish culture on-farm. Thepurposeful production of crops for feeding to fishdirectly, or to livestock, and livestock manurebeing used as pond inputs has shown potential(Figure 25).

However, several factors may hampersynergism between crops, livestock and fish. Inareas with the greatest need for integrated

9.6

Aspects of multipurpose use of a water body involving livestock and fishproduction

Feature Constraints Management

Source of drinking water for fish � Should be low in bacteria, available �Control nutrient inputsand livestock year-round and easily accessible � Excavate a shallow well to filter

waterLarge livestock wallowing in pond � Increased turbidity reduces � Restrict access to shallow end

productivity of pond � Facilitate access though design toreduce physical damage to pond

Water birds swimming � Can cause erosion of pond �Design and location of feeding embankments station and pen

Source of feed for fish and livestock � Competition for direct human food �Consider design to ensure micro-e.g. small fish, snails and shrimp habitats within water bodiesSource of water weeds for fish and � Competition for human food �Design and management to ensurelivestock biodiversity maintained

TABLE 9.2


farming, rural overpopulation may have led toland holding fragmentation, constraining thephysical integration of livestock and cropproduction near the pond. Industrialization andmigration can make the opportunity costs ofgrowing on-farm feeds, raising livestock and/orusing wastes less attractive. Fish may alsocompete with livestock for certain feeds,particularly valuable crop by-products. Somedegree of intensification of livestock may benecessary to make their production viable andtheir wastes more valuable and available for fishculture. Inorganic fertilizers can be profitablyused to ‘spare’ limited amounts of animalmanure, especially when live or fresh fish can bemarketed locally at high prices. A judicious mixof traditional and introduced inputs may often bethe most practical approach.

Rapid economic development in the AsiaPacific over the last two decades has been amajor stimulus to the dynamic growth oflivestock and fish production in the region. Therise of agro-industry and its role in theintroduction of modern strains and feeds havebeen particularly important. Demand and use offormulated, balanced diets has grown rapidly,particularly for pigs and poultry, and to a morelimited extent for cattle. Pingali (1995) explainsthis is a natural result of increasing demand,rising labour and declining transport costs.Where feed industries are established,predicting the development of feed-based or

waste-based aquaculture also becomes a majorissue (Figure 26).

The major challenges are to assess the role oflivestock-fish integration to improve both thelivelihoods of small-scale, rural households and tomake cultured freshwater fish affordable for poorurban consumers.

Source: modified from FAO (1997a)What factors stimulate feed or waste-based aquaculture?

FIGURE 26

Feed mill

Fish

Feed Feed

Waste

Livestock

ACKNOWLEDGEMENTS 159

Acknowledgements

This book is based on research carried out over nearly

two decades and has been prepared over several years. It has drawn on

the support of many people both in the research and writing phases.

Members of the on-station and field research teams based at the Asian

Insitute of Technology (AIT), Bangkok, have been critical to much of the

work synthesized in this text.

The UK Department for International Development (DFID) has

been a major supporter of this work, initially through the secondment of

the authors to AIT and supporting research grants and latterly through the

Aquaculture and Fish Genetics Research Programme. Financial support

was also obtained from other agencies such as USAID and IDRC.

The views expressed in this document are the responsibility of the

authors alone however, and not necessarily endorsed by any of these

organizations.

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