Effect of exogenous enzymes on broiler performance

T. I. Mohamed

Endogenous enzymes

Poultry produced at significant levels ----> Amylase, isomaltase,

maltase, chymotrypsin, pepsin, trypsin and lipase

GIT mircoflora (lower GIT) ---> phytase & fiber hydrolyzing enzymes

Amylase secretion by salivary glands ---> very limited.

Amylase activity in the crop, glandular stomach and gizzard --->

very low limited

Amylase from the duodenum, jejunum to ileum due to a secretion

by the pancreas, intestinal secretions increase

Lipase

The main source ---> pancreas

Bile ---> involved in activation of pancreatic lipase

1- Age

- GIT of young broilers is not fully developed to digest starch –

protein and lipid

Young birds are more limited in types and amounts of enzymes necessary

to utilize a high carbohydrate and vegetable protein diet ----> affecting

nutrient digestibility and the overall performance

-Lower amylase activity in young chicks compared to older birds

---> digestibility of starch in different ingredients is lower in 21-day-

old broilers than in adult.

-Low proteolytic activity (15% lower in 1W chicks compared to 4 w).

- Low lipase activity

Factors affecting Endogenous enzyme activity

2- Enzyme inhibitors (High levels of phytate, fibre (cellulose)

and less digestible protein) in most cereal & leguminous

grains ---> negative effect on digestion of starch – protein –

lipid ---> significantly decrease conc. of amylase, sucrase,

Na+K+-ATPase in the jejunum by 10 to 22%,

High levels of Enzyme inhibitors --> increased pepsin,

chymotrypsin & trypsin production in poultry --> endogenous

amino acid losses

antinutrients as soluble NSPs, ---> increase digesta viscosity

---> decrease fat digestibility and increase coccidiosis.

Corn-Soy Diets and Digestibility

The corn-soy diets became widely fed at the time of serving as reference feed in terms of nutrient composition and digestibility.

The digestibility of energy in corn is relatively high ---> over 90 %

The digestibility of energy in soybean (both meal and full-fat)

energy ---> 70 - 75 %.

This limitation in soya energy yield (and other plant protein sources) associated to the presence of anti-nutritional factors ---> reduced enzyme activity at the animal level.

Thus, enzyme supplementation can improve the energy and nutrient utilization of corn-soy diets

2 major feed enzyme groups:

amylases and proteases ---> produced at significant levels by

poultry.

Other feed enzyme as fibre-hydrolyzing enzymes (NSPases)

and phytase – are not directly produced by the bird

amylase protease increased daily gain and feed intake & FCR

---> due to improve starch & protein digestibility & reduction in

endogenous losses through reduction in endogenous protease

and amylase production.

Relationship between endogenous and feed enzymes

Exogenous enzymes

Definition Enzymes are non living substances,

Biological catalyst,

Act on specific substrate,

Used as feed supplements

Types

- Proteases

- Lipases

- Phytases

- Non Starch Polysaccharidases as xylanases and beta-glucanases ---> widely used in wheat and barley-based and corn-soybean diets

phytase, amylase, and protease enzymes used in various types of poultry diets

Characteristics of ideal enzymes

Specificity of action

Heat stability during the feed preparations

Less expensive

and more safety

Reducing the effects of anti nutritional factors

Objectives of exogenous enz supplementation

Improve fiber digestion.

Improves protein and starch availability.

Improve Digestibility & nutrient utilization.

Reduce intestinal viscosity.

Reduce pathogenic microflora and the improve health.

Reduce feed cost and nutrient excretion.

Improves production Efficiency & decrease production cost

Reducing the need for amino acids and fat supplements

enz supplementation ---> improved nutrient utilization

from diet ---> reduce vegetable oils (high cost) inclusion in

diet ---> significant decrease in input costs

Objective

In addition to viscosity reduction, an increase in the productive value with enzyme supplementation can be achieved by:

Hydrolysis of certain types of carbohydrate-protein linkages and ---> improved availability of amino acids.

Release of available phosphorus from phytate hydrolysis.

Hydrolysis of “resistant starch” and improved energy utilization.

• hydrolyzing enzyme inhibitors found in feed

Depolymerization of cell wall polysaccharides ---> elimination of their nutrient encapsulating effect ---> more effective energy and amino acid utilization.

Release of readily available energy from oligosaccharide hydrolysis.

Decrease environmental pollution by reduction of nitrogen and phosphorus excretion by animals

Application of exogenous enzymes

enzymes that enhance the digestive ability of the animal

newly hatched birds with immature digestive systems in which some enzymes (α-amylase, sucrase, maltase, protease, lipase, etc.) are not produced in sufficient quantities which may result in incomplete utilization of dietary nutrients.

enzymes that are not produced by animal

for hydrolysis of a variety of indigestible components of poultry feeds. Dietary fiber components (i.e., non-starch polysaccharides, glycoproteins), phytate, oligosaccharides or resistant starch undergo a limited conversion to substrates available for absorption and could be degradable by exogenous enzymes of microbial or fungal origin ---> improving the nutritive value of feedstuffs.

Efficacy of Exogenous Enzymes

Efficacy of Exogenous Enzymes depended on

enzymes are specific (substrate)

maintain a given enzyme : substrate ratio

effective when several conditions like temperature, humidity and pH

Formulated diets should be economic (below the recommended nutrient requirements)

Also, Efficacy of Exogenous Enzymes depended on

1- feed ingredient costs

2- enzyme costs

3- dietary specifications

4- bird age

5- ingredient quality

There is a synergistic effect for some enzyme activities

combined phytase and xylanase ---> improve FCR 5.09%

xylanase or phytase alone ---> improve FCR 2.66% and 2.28%,

respectively

•phytase, amylase, protease and xylanase ---> improve FCR 10.4%

of broilers fed a corn-based diet

•phytase only or a mixture of amylase, protease and xylanase only

---> improve FCR a 7.3% and 8.4%, respectively

ACTION OF ENZYMES Phytases :Liberate Inorganic Phosphate

From Bound Phytate

P P

P

P P

P P

P

P

P

+ P Phytase

Non Starch Polysaccharides

Cereals & byproducts:

Xylan

Beta glucan

Cellulose

Starch

Lipids & Phytate

Legumes & meals

Pectins

Alphagalactosides

Cellulose

Protein

Lipids & Phytate

NSP’s based on Solubility

SOLUBLE NSP’s Responsible for increase in viscosity of gut.

Slow down the intestinal transit time

Proliferation of fermentative organisms

Adverse Effect

High gut viscosity decreases the rate of diffusion of nutrients.

enzymes and Functions

Enzyme Substrate Effects

Cellulase cellulose Degradation of cellulose

β-Glucanase

β-glucans Reduction of intestinal digest viscosity

Pectinase Pectins Reduction of intestinal digest viscosity

Xylanase xylans Reduction of intestinal digest viscosity

Galactisidases Galactisideses Reduction of intestinal digest viscosity

Phytase Phytic acid Reduction of intestinal digest viscosity and degradation of phytate

Effect of pentosanase on broiler chicks fed a wheat-based diet

parameter control Pentosanase

(1000XU/ kg SED P Value

Daily gain,g 34a 36.6 b 0.475 0.001

Daily intake,g 54a 54.8 b 0.641 0.05

Feed efficiency

0.634 a 0.657 b 0.003 0.001

Effect of a soy-specific enzyme cocktail containing protease and cellulase on broilers fed a wheat, soydiet

parameter control Enzyme supplemented

Weight gain 15 days (g) 549 569

Weight gain 29 days (g) 1463 1500

FCR 15 days (g ) 1.617 a 1.559 b

FCR 29 days (g ) 1.63 a 1.707 b

Effect of exogenous enzyme on fat digestibility of chicks

Treatment Fat digestibility

Control diet (corn soy diet) 81 b

HOASS 75.2 d

HOASS + Lipase (L ) 76.8 c

HOASS + phosphoLipase (P )

79.5 b

HOASS +L+P 80.2 b

HOASS=high oleic acid sunflower seed 250g/kg

Effect of xylanase on fat digestibility and intestinal viscosity

parameter Soy oil Soy oil + Xylanase

Weight 21 days (g ) 681 a 761 b

FCR 0-21 days 1.392 ab 1.266 b

Jejunal viscosity (mpa,s) 438 32

CF digestibility 82.3 a 87.3 b

Effect of beta-glucanase on broiler performance fed a barley-based diet (to 39 days). Diet contains 50%barley containing

4.3% beta-glucan

Enz level

u/ kg feed

Feed intake

g

Body weight, g

FCR

0 96.5 a 2163 a 1.742 a

100 95 ab 2193 ab 1.692 b

200 95.3 ab 2215 b 1.678 b

400 93.2 b 2160 a 1.685 a

Conclusion

Exogenous enzyme supplementation

improve digestibility�

Flexibilization of feed formulation�

Increase availably of low quality ingredient

�Reduced production cost

Thank you