OPPORTUNITIES FOR RENDERED PRODUCTS IN ......Year by year, the aquaculture becomes larger and more intensive So if we’re raising more fish, we’re obviously going to need more feed,
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OPPORTUNITIES FOR RENDERED PRODUCTS IN AQUACULTURE Advancing science & industry through partnership Jesse T. Trushenski CENTER FOR FISHERIES, AQUACULTURE, & AQUATIC SCIENCES
OPPORTUNITIES FOR RENDERED PRODUCTS IN AQUACULTURE
Advancing science & industry through partnership
Jesse T. Trushenski
CENTER FOR FISHERIES, AQUACULTURE, & AQUATIC SCIENCES
Presenter
Presentation Notes
Good morning, everyone. I’m going to continue to address the question, “Is aquaculture sustainable?”, but I’m going to focus on nutritional inputs. But as I began to assemble this talk, I realized that much of what I was hoping to do was to correct misconceptions about aquaculture, U.S. aquaculture in particular, hence my subtitle, “Mythbusting feed, food, and the future.”
THE WORLD IS HUNGRY
We will need 60% more food by 2050 Population growth, urbanization, and changing diets driving shifts in
per capita consumption and eating habits WHO 2002, CGIAR CCAFS 2013
CGIAR CCAFS 2013
Presenter
Presentation Notes
First, let us recall the mandate for aquaculture. The world is hungry, and increasingly hungry for protein. There are just over 7 billion of us on the planet at this time, and over the next 4 decades or so, it is estimated that our ranks will swell to more than 9.5 billion. By the next century, the human population will be nearly 11 billion strong. Based on population growth, we will need to be producing 60% more food by 2050. Not only will we need more food in general, we will need a lot more animal protein in particular. Increasing urbanization, lower production costs, greater buying power, and the like have led to increases in total per capita consumption of animal protein—whereas we need 60% more food by 2050, we need 60% more animal protein much sooner, by 2030.
WHERE IS OUR SEAFOOD COMING FROM?
We are unlikely to get more food from our oceans 80% of fish stocks are fully exploited or in decline FAO 2012
Presenter
Presentation Notes
Seafood is an essential source of dietary protein, and up until relatively recently, almost all of it came from capture fisheries. However, since the 1990s, capture fishery landings have been relatively static. 80% of fish stocks throughout the world are either fully exploited—in other words they can’t be fished any harder without negative consequences—or they are in decline. Now, the more optimistic of you might say, well, that means there’s still another 20% that could be developed. That’s true, but there’s a reason these fisheries haven’t been fully developed yet. A good example would be the Antarctic krill fishery: this fishery is underexploited is because the fishing grounds are remote, it’s logistically challenging fishing, and the product—which is not generally used for human consumption—doesn’t hold up well during the long trip back to port. Bottom line, we are unlikely to get any more food from capture fisheries—if anything, in the future, we may get less. Nonetheless, seafood demand has continued to climb, and aquaculture has grown dramatically over the past few decades to close this gap. Currently, half of the world’s seafood comes from farms.
AQUACULTURE PRODUCES PROTEIN EFFICIENTLY
Swine 3 to 1
Beef Cattle 8 to 1
Poultry 2 to 1
Fish 1-1.5 to 1
Fish beat terrestrial livestock in both feed conversion efficiency and dress-out
50-60% of a salmon carcass is edible compared to 40% for beef
Presenter
Presentation Notes
You may be saying, “Yes, well, that’s all very good, and aquaculture is certainly important in the context of seafood supply, but is it really important in the context of global protein supply?” Well, I doubt that any of you would consider cattle to be a minor contributor to global meat production, so consider this—farms now raise more seafood than beef. Not only does the aquaculture industry produce more meat than the cattle industry, we do so more efficiently, which brings us to our first element of sustainability—feed conversion ratios. Feed conversion ratios are a measure of how efficiently an animal grows, and is a simple ratio of the amount of feed offered to the amount of weight gained. For swine, the FCR is usually about 3: 3 pounds of feed for every one pound of gain. For cattle, it’s about 8:1—bear in mind, this is for cattle on a feedlot, the value is actually much higher for grass-fed beef. Poultry are substantially more efficient, packing on a pound for every 2 pounds of feed they eat. But fish, because they do not expend energy to maintain their body temperatures, are the most efficient, capable of achieving 1:1 conversions. Not only do fish beat terrestrial livestock in terms of FCR, they also beat them in terms of dress-out. As much as 60% of a salmon carcass is edible, whereas only about 40% of a steer is. So, our aquatic livestock gain weight more efficiently, and more of what they gain can be directly translated to our dinner table. In terms of doing more with less—a key element of sustainability—aquaculture is the most efficient means of transforming feed-grade protein in to food-grade protein.
GLOBAL AQUACULTURE IS DIVERSE
Annual Production (MMT)
Freshwater Fish
Mollusks
Crustaceans
Marine Fish
Other
FAO 2014
More than 500 species are raised
worldwide Including more than 400 finfishes and crustaceans
Presenter
Presentation Notes
A number of you might not be familiar with the aquaculture industry, I thought it would be useful to introduce you to some of the more popular taxa cultured throughout the world.
0
20
40
60
80
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1995 2000 2005 2020
Total Aquafeed Production (MMT)Aquaculture Production Using Compound Feeds (%)
INCREASING RELIANCE ON COMPLETE FEEDS
Tacon and Metian 2008
Aquafeed manufacturing is outpacing aquaculture Year by year, the aquaculture becomes larger and more intensive
Presenter
Presentation Notes
So if we’re raising more fish, we’re obviously going to need more feed, but the demand for feed is actually going to grow faster than the aquaculture industry is in general. This is because the industry is growing progressively more intensive and reliant on compound feeds. In the mid-1990s, more than half of the fish raised weren’t fed much of anything at all. Most of the industry focused on filter feeders that could subsist simply on phytoplankton and zooplankton in fertilized ponds. But this form of extensive aquaculture is growing less important, and more and more farms are switching to compound feeds as the primary source of nutrition for their fish. This is why you see this dramatic uptick in projected aquafeed production at the end of the graph—the industry is growing, yes, but it’s also becoming more intensive and reliant on compound aquafeeds.
THE CHALLENGES OF FEEDING FISH
Omnivores Carnivores
Nut
ritio
nal D
eman
ds
Swine
Tilapia
ProteinLipidOther
Poultry
Presenter
Presentation Notes
The efficiency of fish does come at a certain price, however, and this brings us to the challenges of feeding fish. The aquaculture industry is staggeringly more diverse than any other form of livestock production. Poultry is probably the second-most diverse, and what do they raise? Chickens, turkeys, ducks, geese…beyond those first four, it becomes a bit more difficult to think of what comes next. In aquaculture, more than 500 species are produced throughout the world, including more than 300 finfish, running the gamut from omnivores like tilapia, to mid-range carnivores like trout, to apex predators like tuna. Not only does the species diversity make it challenging to identify nutritional demands and tolerances for all of these different fish, as we move along this spectrum, the nutritional demands of the fish increase, making it more challenging to meet these demands in an economically and environmentally sustainable manner. However, it’s important to recognize that even the species that we would consider to be easy-keepers, like tilapia, are considerably more costly to feed than terrestrial livestock because they demand more protein and fat in their diet. Whereas protein makes up about a third or more of a tilapia diet, whereas it’s only 15-20% of poultry and swine diets. So, again, the efficiency of fish is striking, but fueling that efficient growth is not without its challenges.
FISH HAVE HIGH PROTEIN DEMANDS But require amino acids, not protein
Species Dietary Protein %) Species Dietary Protein (%)
Asian sea bass 45 Freshwater basses 35-47
Atlantic halibut 51 Trouts 40-53
Atlantic salmon 55 Flatfishes 50-51
Tilapias 30-40 Catfish 32-36
Pacific salmonids 40-45 Beef cattle 7-18
Carps 31-43 Dairy cattle 12-18
Eels 40-45 Sheep 9-15
Sea basses 45-50 Swine 12-13
Sea breams 50-55 Poultry 14-28 Halver and Hardy 2002
Presenter
Presentation Notes
But even the easy keeper herbivorous and omnivorous fishes have high demands relative to traditional terrestrial livestock. These tables show the typical dietary protein inclusion rates for a range of fish species, and as you can see, the more carnivorous the fish, the more protein it demands. But even the lowest values—for tilapia and catfish, for example—are higher than those for the terrestrial livestock Given that protein is the most expensive part of any livestock ration, you can see that this presents a challenge. But, of course, we must remind ourselves that fish don’t require protein, but rather the amino acids that proteins contain. .
ESSENTIAL AMINO ACID REQUIREMENTS
Essential Amino Acids
Estimated Requirement (Rainbow Trout)
Fish Meal Composition
Arginine 3.3-5.9 6.2
Histidine 1.6 2.8
Isoleucine 2.4 4.2
Leucine 4.4 7.2
Lysine 3.7-6.1 7.8
Methionine 1.8-3.0 3.4
Phenylalanine 4.3-5.2 3.9
Threonine 3.2-3.7 4.2
Tryptophan 0.5-1.4 0.8
Valine 3.1 5.0
Data expressed as % crude protein Halver and Hardy 2002; Omega Protein, Inc. 2006
Presenter
Presentation Notes
This table shows the estimated essential amino acids requirements for rainbow trout—one of the few species we have relatively complete information for. Without getting bogged down in the details, what I want you to take away from this is the similarity between the estimated requirements and the levels that are found in the most commonly used protein source in aquafeeds, fish meal. As you can see, the requirements of the fish match up very nicely with the composition of fish meal, which is partly why fish meal is known as the “ideal protein” in aquaculture nutrition.
FISH ALSO HAVE HIGH LIPID DEMANDS But require fatty acids, not lipid
Species Dietary Lipid (%) Species Dietary Lipid (%)
But even the easy keeper herbivorous and omnivorous fishes have high demands relative to traditional terrestrial livestock. These tables show the typical dietary protein inclusion rates for a range of fish species, and as you can see, the more carnivorous the fish, the more protein it demands. But even the lowest values—for tilapia and catfish, for example—are higher than those for the terrestrial livestock Given that protein is the most expensive part of any livestock ration, you can see that this presents a challenge. But, of course, we must remind ourselves that fish don’t require protein, but rather the amino acids that proteins contain. .
Presenter
Presentation Notes
To understand fatty acid requirements, we’re going to have to talk just a little bit about biochemistry. I promise to make this as brief and painless as possible. This figure shows the biosynthetic pathways from 18:0, a saturated fatty acid, to the n-3 and n-6 long-chain polyunsaturated fatty acids. The first step is transforming 18:0 into 18:1n-9 through the action of delta 9 desaturase—that’s easy enough to do, but the next step, transforming 18:1n-9 to 18:2n-6 or 18:3n-3 via delta 12 or delta 15 desaturase, that’s where we first run into trouble. These transformations are not known to be made by any vertebrate, including fish. From each, through a series of enzymatic steps, 18:2n-6 and 18:3n-3 can be transformed into the LC-PUFA ARA, EPA, and DHA. These transformation are made by some fish, but not other fish, or at least, not all fish biosynthesize LC-PUFA from 18-carbon precursors in appreciable amounts.
Limited physiological functions
Distinct physiological functions
Presenter
Presentation Notes
To understand fatty acid requirements, we’re going to have to talk just a little bit about biochemistry. I promise to make this as brief and painless as possible. This figure shows the biosynthetic pathways from 18:0, a saturated fatty acid, to the n-3 and n-6 long-chain polyunsaturated fatty acids. The first step is transforming 18:0 into 18:1n-9 through the action of delta 9 desaturase—that’s easy enough to do, but the next step, transforming 18:1n-9 to 18:2n-6 or 18:3n-3 via delta 12 or delta 15 desaturase, that’s where we first run into trouble. These transformations are not known to be made by any vertebrate, including fish. From each, through a series of enzymatic steps, 18:2n-6 and 18:3n-3 can be transformed into the LC-PUFA ARA, EPA, and DHA. These transformation are made by some fish, but not other fish, or at least, not all fish biosynthesize LC-PUFA from 18-carbon precursors in appreciable amounts.
Freshwater
Euryhaline
Saltwater
Trophic Level 1 2 3 4 5
FEEDING HABITS DRIVE REQUIREMENTS
Presenter
Presentation Notes
To understand fatty acid requirements, we’re going to have to talk just a little bit about biochemistry. I promise to make this as brief and painless as possible. This figure shows the biosynthetic pathways from 18:0, a saturated fatty acid, to the n-3 and n-6 long-chain polyunsaturated fatty acids. The first step is transforming 18:0 into 18:1n-9 through the action of delta 9 desaturase—that’s easy enough to do, but the next step, transforming 18:1n-9 to 18:2n-6 or 18:3n-3 via delta 12 or delta 15 desaturase, that’s where we first run into trouble. These transformations are not known to be made by any vertebrate, including fish. From each, through a series of enzymatic steps, 18:2n-6 and 18:3n-3 can be transformed into the LC-PUFA ARA, EPA, and DHA. These transformation are made by some fish, but not other fish, or at least, not all fish biosynthesize LC-PUFA from 18-carbon precursors in appreciable amounts.
Freshwater
Euryhaline
Saltwater
Trophic Level 1 2 3 4 5
FEEDING HABITS DRIVE REQUIREMENTS
Presenter
Presentation Notes
To understand fatty acid requirements, we’re going to have to talk just a little bit about biochemistry. I promise to make this as brief and painless as possible. This figure shows the biosynthetic pathways from 18:0, a saturated fatty acid, to the n-3 and n-6 long-chain polyunsaturated fatty acids. The first step is transforming 18:0 into 18:1n-9 through the action of delta 9 desaturase—that’s easy enough to do, but the next step, transforming 18:1n-9 to 18:2n-6 or 18:3n-3 via delta 12 or delta 15 desaturase, that’s where we first run into trouble. These transformations are not known to be made by any vertebrate, including fish. From each, through a series of enzymatic steps, 18:2n-6 and 18:3n-3 can be transformed into the LC-PUFA ARA, EPA, and DHA. These transformation are made by some fish, but not other fish, or at least, not all fish biosynthesize LC-PUFA from 18-carbon precursors in appreciable amounts.
All the building blocks must be available before new molecules or
tissues can be synthesized
GROWTH HAPPENS WHEN LIMITING RESOURCES BECOME AVAILABLE AND IS AS FAST AS THE SLOWEST PROCESS
Protein
Lipid Carbohydrates
Micro-nutrients
Presenter
Presentation Notes
We’ve only talked about nutrient requirements in terms of amino acids and fatty acids—a fish feed has to contain a lot more than that, including vitamins, minerals, etc. Each of these nutrients can become a limiting factor. You can think of this as putting the pieces together into a puzzle, or playing a game of Tetris—you’re not going to make any progress until all the pieces are in place. Whether it’s an essential amino acid, a vitamin, or simply energy that is limiting, fish growth can only be as fast as the slowest process or as fast as those puzzle pieces drop into place.
Macro- & Micronutrients
Metamorphosis
Reproduction
Behavior Stress
Response
Biosynthetic Rates
Cell Signaling
Appetite Regulation
Osmoregulation
Growth & Development
Energy Substrates
Immunity & Survival Antioxidative
Defense
Seafood Quality
Endocrine Status
Metabolic Regulation
Pigmentation
Membrane Competence
Tocher 2003, Li et al. 2008
WHAT DO WE FEED FISH?
Protein
Lipid Carbohydrates
Micro-nutrients
Typical Ingredients
High Energy (Carnivorous)
Medium Energy (Carnivorous)
Low Energy (Omnivorous)
Fish meal 25-50 20-40 0-20
Soyproducts 0-15 25-35 30-50
Gluten& animal products
5-20 15-20 15-20
Cerealgrains 10-18 20-25 30-45
Fats/oils 20-30 5-10 2-5
Other 3-5 3-5 3-5
Presenter
Presentation Notes
With those challenges in mind, what do we actually feed fish to provide them with the balance of protein, lipid, carbohydrate, and micronutrients they need to growth and thrive? Well, of course, it depends on the species, but we can generally categorize their feeds as being high energy (for high level carnivores), medium energy (for medium-level carnivores), or low energy (for omnivores and herbivores). Although different fish have different demands, their diets often contain the same ingredients, albeit in different proportions. Because fish have such high protein demands, our diets have to contain relatively protein dense ingredients—usually, if an ingredient has less than 20-30% protein, it’s not going to have much value in a typical aquaculture feed. This is why our diets contain ingredients like fish meal, soy products, plant glutens and rendered animal products. We also include various fats and oils to provide essential nutrients and energy. Proteins and lipids—they are necessary to meet the demands of aquatic livestock, but they also drive up the price of our feeds.
THE RISING COST OF FISH MEAL
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500
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2500
1985 1990 1995 2000 2005 2010
Price in $US/MT
“…much research has focused on finding replacements for fish meal…Partial replacements have been achieved. However, no dramatic breakthroughs have been reported, and the share of fish meal and fish oil used in aquaculture is increasing…” FAO 2008
Aquaculture consumes ~61% of global supply
Presenter
Presentation Notes
One of the major drivers of increasing feed cost is fish meal. Fish meal is a protein source that derived from the so-called reduction fisheries. These are small marine pelagics such as anchovies and menhaden that are harvested and rendered into feed-grade proteins and oils, which have a variety of industrial and agricultural uses. Up until fairly recently, fish meal was a very cost-effective source of high quality protein. It remains a highly nutritious ingredient, but like other marine fisheries, reduction fishery landings are largely static, and as demand has increased, the price has gone up. I think it’s important to note that while price is a problem, it’s not the only issue. Although we are increasingly using fish meal more judiciously, aquaculture currently consumes about 2/3 of global fish meal production. We need to produce more fish, which means we are going to need more feed, but we can’t do that sustainably by commanding more of the fish meal market. For all the end-users of fish meal, the problem in the future won’t necessarily be its price, but that there isn’t enough to go around at any price.
THE RISING COST OF FISH OIL
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1000
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2000
2500
2008 2009 2010 2011 2012
“…given the difficulty in replacing fish oils…it is clear that competition for fish oil is likely to be a more serious obstacle for some sections of the aquaculture industry.” FAO 2008
Fish Oil Price in $US/MT
Aquaculture consumes ~74% of
global supply
Presenter
Presentation Notes
The same is true of fish oil, which also comes from the same reduction fisheries. At this point, the aquaculture industry uses about ¾ of the available fish oil, and so here again, our industry faces a significant bottleneck. Now, you may be thinking, “Well, this doesn’t paint a particularly rosy picture of the aquaculture industry.” And to some extent, that’s true--fish meal and fish oil are finite resources which our industry increasingly monopolizes. When we talk about sustainability, it’s important to be earnest and to address constraints directly—this is a constraint, but as we’ll discuss in a few minutes, one that is being addressed.
FEEDSTUFF ATTRIBUTES TO CONSIDER
Compositional profile and practical feeding value
Protein content and quality Carbohydrate levels Presence of antinutritional factors
Economic and environmental costs of raw materials
Availability Cost-effectiveness relative to marine ingredients AND other feedstuffs Sustainability
Influence on product quality Nutritional value Safety
FEEDSTUFF ATTRIBUTES TO CONSIDER
Compositional profile and practical feeding value
Protein content and quality Carbohydrate levels Presence of antinutritional factors
Economic and environmental costs of raw materials
Availability Cost-effectiveness relative to marine ingredients AND other feedstuffs Sustainability
Influence on product quality Nutritional value Safety
CARBOHYDRATES IN AQUAFEEDS
Digestion is limited by enzyme production Utilization is limited by ability to metabolize effectively
Laporte et al., unpublished data
ANTINUTRITIONAL FACTORS IN AQUAFEEDS
Protease inhibitors—reduce protein digestibility Lectins—irritate the intestinal epithelium Phytic acid—reduces protein and phosphorus digestibility Saponins—toxic, reduce feed intake Antigenic compounds—cause allergic responses
Burrells et al. 1999, Francis et al. 2001
≤50% soy diet ≥80% soy diet
SUSTAINABILITY & MARKETING OF FARMED FISH
Customers and retailers are increasingly focused on sustainability criteria Fish meal/fish oil usage negatively affects rankings
SAFETY OF FARMED FISH
Risk outweighed by benefits of seafood consumption
National Academies Institute of Medicine Food and Agriculture Organization World Health Organization
BUT, perception is reality and feeding rendered fats can reduce contaminant burdens
Although there is variability in levels, marine ingredients are potential sources of organic and inorganic contaminants
Risks of contaminants in farmed fish are largely overblown
Presenter
Presentation Notes
One of the other issues that comes up with respect to fish meal and fish oil sparing is the accumulation of environmental contaminants in farmed fish. There is certainly variability among products, but fish oil is a potential source of persistent organic pollutants that can accumulated in farmed fish. First, let me say that the risk of contaminants in farmed fish is largely overblown and what little risk is there is far outweighed by the benefits of seafood consumption. However, perception is reality, and in the eyes of the public, the more we can do to reduce the already low levels of contaminants in farmed fish, the better.
FISH OIL SPARING & NUTRITIONAL VALUE
Trushenski et al. 2011
Fish oil sparing affects fillet
composition and associated
nutritional value
0
0.5
1
1.5
2
2.514:0
16:0
18:0
SFA
16:1n-7
18:1n-7
18:1n-9
MUFA18:2n-6
18:3n-3
MC-PUFA
20:4n-6
20:5n-3
22:5n-3
22:6n-3
LC-PUFA
Line of Equality
67% FO
33% FO
0% FO
MINIMIZING LOSS OF NUTRITIONAL VALUE
No growth effects Substantial LC-PUFA loss
Trushenski and Boesenberg 2009
No growth effects Limited LC-PUFA loss
Trushenski et al. 2008
No growth effects Limited LC-PUFA loss
Trushenski 2009
n-3 MC-PUFA
SFA
MUFA/SFA
Presenter
Presentation Notes
We’ve seen this kind of thing before—when we fed HSB diets containing flaxseed oil, which contains a lot of MC-PUFA, we saw now growth effects, but the fillets showed a substantial loss of LC-PUFA. But when we fed coconut oil and palm oil—which are rich in SFA and MUFA—we saw relatively little loss of LC_PUFA from the fillets. So, here is one approach to try to minimize the effects of fish oil sparing on product quality.
RENDERED FATS HELP MAINTAIN NUTRITIONAL VALUE
Gaus
e an
d Tr
ushe
nski
201
3
RENDERED FATS HELP MAINTAIN NUTRITIONAL VALUE
Gaus
e an
d Tr
ushe
nski
201
3
RENDERED FATS MAY ALSO MAKE FATTY ACID REQUIREMENTS EASIER TO ATTAIN
Trushenski et al. 2013 400
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800
0 5 10 15 20 25 30 35 40
Wei
ght G
ain
(%)
Dietary LC-PUFA Content (g/kg diet)
Break Point = 29.3 g LC-PUFA/kg diet
400
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500
550
600
650
700
750
800
0 5 10 15 20 25 30 35 40
Wei
ght G
ain
(%)
Dietary LC-PUFA (g/kg diet)
Growth was suppressed among fish fed high
levels of C18-rich soybean oil, but not SFA-rich
soybean oil
RENDERED FATS MAY ALSO MAKE FATTY ACID REQUIREMENTS EASIER TO ATTAIN
Sparing fish oil with beef tallow does not impair performance in the way that sparing with other lipids does
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Fish Oil(+)
Control
BeefTallow (-)Control
BeefTallow +
DHA
Atlantic Salmon
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Fish Oil(+)
Control
BeefTallow (-)Control
BeefTallow +
DHA
Pompano
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Fish Oil(+)
Control
BeefTallow (-)Control
BeefTallow +
DHA
Hybrid Striped Bass
Weight Gain (%) Trushenski et al., unpublished data Trushenski et al., unpublished data Turchini et al., unpublished data
THE CHALLENGES…
Fish meal and oil are finite resources which aquaculture increasingly monopolizes
Sources of amino acids abound, but may be improperly balanced, unpalatable
Alternative proteins impact production performance, livestock resilience, etc.
Sources of essential fatty acids can be limiting
Alternative lipids affect fillet nutritional value, product safety, reproductive performance, etc.
THE OPPORTUNITIES…
Strategic use of resources including rendered animal products
solves problems
ACKNOWLEDGMENTS
Authors of the various works cited herein Fats and Proteins Research Foundation Center for Fisheries, Aquaculture and Aquatic Sciences
