Enzymes in poultry nutrition & it's performance

1. Exogenous Enzymes in Poultry Nutrition
Supervisor: Dr. M. Daneshyar
By: M. Behroozlak
Jan. 2014

2. Introduction
Antibiotics have been used in poultry feed for
improving growth performance, preventing some
specific pathogenic microorganism and increasing
some useful microorganism in intestinal microflora
over the years.
However, antibiotics used as growth promoters in
animal feeds have been banned recently due to
potential development of antibiotic resistant human
pathogenic bacteria.

3. Introduction
Nowadays, the possibility of using new natural alternative
additives instead of antibiotics in animal diets is being researched.
Prebiotics
Organic
Acids
Peptides Growth
Promotores
(Enzymes(
Replacements of Antibiotic Growth Promotores (AGPs(
Probiotics Phytobiotics

4. Exogenous Enzymes
• Traits of Exogenous Enzymes (EE(
Enzymes are one of the many types of protein in biological
systems. Their essential characteristic is to catalyze the rate of a
reaction but is not themselves altered by it. They are involved in all
anabolic and catabolic pathways of digestion and metabolism.
Enzymes are not living organisms and are not concerned about
viability or cross infection. They are stable at 80-85 degree
centigrade for short time.

5. Exogenous Enzymes
It is common practice to name enzymes by adding the suffix ase to
the name of the principal substrate. For example, β-glucanase is an
enzyme that splits β-glucans, and proteases break protein.
Categorize of enzymes
1. Digestive enzymes as endogenous
enzymes
2. Exogenous enzymes
(those administrated from
outside(

6. Sources of EE
Microorganisms that generally involved in production of
enzymes are :
Bacteria
Fungus
Yeast
Bacillus subtilis, Bacillus lentus, Bacillus
amyloliquifaciens and Bacillus stearothermophils
Triochoderma longibrachiatum, Asperigillus
oryzae and Asperigillus niger
S. cerevisiae

7. Use of enzymes in animal feed
Consistent increase in the price of feed ingredients has been a
major constraint in most of the developing countries.
As a consequence cheaper and nonnconventional feed ingredients
have to be used which contain higher percentage of Non-Starch
Polysaccharides (soluble and insoluble/crude fibre) along with
starch.
Non Starch Polysaccharides (NSPs) are polymeric carbohydrates
which differ in composition and structure from starch (Morgan
et al., 1995) and possess chemical cross linking among them
therefore, are not well digested by poultry.

8. NSPs
• A part of these NSPs is water-soluble which is notorious for
forming a gel like viscous consistency in the intestinal tract (Ward,
1995) thus by reducing gut performance.
• Predominantly water soluble and viscous arabinoxylans, which
belong to pentosan group, are assumed to be the factor responsible.
These pentosans also greatly increase the water intake by the
birds, which lead to unmanageable litter problems caused by wet
and sticky droppings.
This deteriorates the hygienic conditions and
carcass quality.

9. NSPs
On the other hand, β-glucans adversely affect all nutrients,
especially protein and starch utilization and are known to give
rise highly viscous conditions in the small intestine of the chicks.
Poultry do not produce enzymes for the hydrolysis of Non-Starch
Polysaccharide present in the cell wall of the grains and they
remain un-hydrolyzed.
The poultry industry readily accepts enzymes as a standard dietary
component, especially in wheat and barley-based rations.

10. NSPs
Classification of NSPs

11. NSPs
The NSPs are the major components of the cell wall of cereals. Some of
them located mainly in endosperm cell walls of cereals are soluble and
others are insoluble.

12. NSPs
These NSPs are soluble in water producing viscous solutions (Figure 2.1).
Increased viscosity of the fluid film surrounding the villi of rat jejunum
gave rise to a thickening of the rate-limiting unstirred layer.
This caused accumulation of nutrients and a reduction of nutrient digestion
and absorption in vitro .

13. Unstirred Water Layer

14. NSPs
NSPs not only affects the absorption of basic nutrients such as
glucose, fatty acids and amino acids, but also affects the utilization
of certain minerals, such as calcium, phosphorus and zinc. Studies
demonstrated that the endogenous secretion of water, proteins,
electrolytes and lipids can be increased markedly by adding NSPs to
the diet.

15. Wheat
Barley
Corn
Sorghum

16. Defects of
NSPs for
poultry

17. NSPs Enzymes
The most important enzymes in the poultry feed industry today are
β-glucanase, xylanase and phytase.
They are widely used in poultry diets containing barley, oats, rye or
wheat to improve feed utilization by removal of the anti-nutritional
effects of NSPs contained in these cereal raw materials.
Enzymes break down the NSPs, decreases intestinal viscosity
and eventually improve the digestibility of nutrients by
improving gut performance.

18. NSPs Enzymes improved performance

19. NSPs Enzymes

20. The Use of Enzymes in Corn-SBM
Poultry Rations
The nutrients contained in corn and soybean meal are generally
considered to be highly digestible. Heat treatment is commonly used to
inactivate antinutritive factors (ANFs) such as protease inhibitors and
lectins in soybean meal (Campbell and van der poel, 1998).
However, the energy utilization in corn and soybean meal also depends
on the amount of indigestible carbohydrates present, particularly
oligosaccharides.
The inclusion of high concentrations of soybean meal as the sole protein
source in broiler diets can adversely affect growth performance (Irish and
Balnave, 1993).

21. The Use of Enzymes in Corn-SBM
Poultry Rations
In addition, some of ANFs in soybean, such as antigenic proteins and
phytate cannot be reduced or alleviated by heat.
With the recent developments in feed enzyme technologies, many
microbial enzymes such as phytase, amylase, protease and α-
galactosidase, have been used into corn-soybean meal-based diet either
to improve digestibility of nutrients or to reduce the ANFs.
Most of the stored phosphorus in plants is found in seeds, mainly as
phytate phosphorus. In corn, 90% of the phosphorus is present as
phytate, and in soybean meal 75% of the phosphorus is present as phytate
Phytate

22. Phytate
Phytate phosphorus is poorly available (30%) to monogastric animals,
including poultry, due to the absence of adequate levels of endogenous
enzyme phytase or phosphatase.
Actually, phytate is often considered toxic, or antinutritive because it is
capable of binding di- and divalent cations such as Ca, Co, Cu, Fe, Mg,
Mn, Ni and Zn in very stable complexes and reducing the availability of
these minerals to the animal . In addition, phytate may form complexes
with proteins and starches and may also reduce the availability of these
nutrients from the diet .
Dietary supplementation with microbial phytase is well established as
an effective and practical method of improving phytate digestibility in
production animals. In poultry, microbial phytase supplementation
generally results in a 20-45% improvement in phytate-P utilization.

23. Benefits of Enzymes
Benefits of using feed enzymes to poultry diets include :
Reduction in digesta viscosity,
Enhanced digestion and absorption of nutrients especially fat and protein,
Improved Apparent Metabolizable Energy (AME) value of the diet,
Increased feed intake, weight gain, and feed–gain ratio,
Reduced beak impaction and vent plugging,
Decreased size of gastrointestinal tract,
Altered population of microorganisms in gastrointestinal tract,
Reduced water intake, reduced water content of excreta, reduced production
of ammonia from excreta, reduced output of excreta, including reduced N
and P.

24. Effect of EE on GIT Charastristics
Effect of EE on
 Digestive organ sizes
 Morphometric traits of GIT
 Digestive enzymes activities

25. Effect of EE on GIT Morphology in
Wheat- SBM diet
A growth trial were conducted to investigate the effects of dietary
enzyme supplementation (xylanase and β-glucanase) on, intestinal
morphology, digestive organ size of broiler chickens fed wheat-
based diets.
The experimental diets in both trials consisted of a wheat- soybean
based control diet supplemented with 0, 200, 400, 600, 800, or 1,000
mg/kg enzyme. Diets were given to the birds from d 7 to 42 of age.
Study 1

26. Effect of EE on GIT Morphology
Enzyme inclusion decreased the size of the digestive organs and the
gastrointestinal tract to some extent. The relative length of each
intestinal segment decreased linearly (P < 0.05).
The relative weight of the anterior intestine on d 21 and ileum on d
42 also decreased linearly (P < 0.01).
On d 21 and 42, there were negative linear (P < 0.05) relationships
between increasing enzyme supplementation and the relative weight
of the liver and pancreas, respectively.

28. Effect of EE on GIT Morphology
When supplementing exogenous enzymes in the wheat control
diet, a greater proportion of NSP may be hydrolyzed, which might
attenuate the secretory function of the responding organs and GIT
segments, and then the organ sizes may decrease.
Brenes et al. (1993) also implied that:
The reduction in relative organ weight had a direct
economic benefit, as the dressing yield of broilers should
increase proportionally.

29. Effect of EE on GIT Morphology in
Corn-SBM diet
The study was conducted to compare the effects of XG (xylanase + β-
Glucanase) with AG (galactosidase) and BM (β-mannanase) at different
metabolizable energy diets on digestive physiology of broilers fed with
corn-SBM diet.
A 2 × 4 factorial design was used with two basal diets (the positive control
group, PC; negative control with ME reduction 100 kcal/kg, NC) and
with or without the addition of three exogenous enzymes (No enzyme diet;
0.02% BM; 0.01% AG; 0.05% XG) respectively.
Study 2
Two diet with four enzyme levels

30. Effect of EE on GIT Morphology in
Corn-SBM diet
For assessment of morphometric tratis:
At 21 and 42 day of age 2.0 cm-long samples from duodenum and ileum
were taken to measure the villus length and crypt depth, and the villus
length to crypt depth ratio (V/C) was calculated by the method of Lei
(2009).
For assessment of endogenous enzymes activity :
One broiler per replicate was chosen and fed for 2 h. After 4 h feeding, the
intestinal contents of the duodenum plus jejunum were collected and stored
at −20°C for analysis of trypsin, chymotrypsin, lipase, and amylase
activities according to the method of detection kit instructions from Nanjing
Jiancheng Bioengineering Institute.
Digestive physiology:

31. Effect of EE on GIT Morphology in
Corn-SBM diet
The crypt depth (in duodenum) was significantly decreased by the
addition of enzymes (AG ) in the PC diet at 21d (P <0.05). The V/C
was significantly increased by PC diet at 21 d, and the addition of
AG increased V/C (P <0.05) at 21d (Table 6).
The villus length and V/C of ileum were significantly increased by
the addition of BM or XG (Table 7).
XG improved the activities of trypsin, chymotrypsin and amylase,
BM improved the activity of trypsin at 21d, and AG improved the
activity of chymotrypsin at 21d (Table 8).
Results:

34. Crypt depth
Large crypt suggests a high nutrient requirement for intestinal
maintenance and reduced efficiency of then bird and explain the
poor growth performance. It has been reported that enzyme
supplementation can lower the rate of cell proliferation in the
crypt (Silva and Smithard, 2002).
The lower crypt depth as a result of enzyme addition can be
considered as a beneficial way to decrease the cost of intestinal
maintenance in birds.

36. Villi & Crypt depth

37. Effect of EE on GIT traits & Blood
metabolites
There were four treatments: the control diet and the other three enzyme
complex supplemented diets which were 180 mg/kg, 360 mg/kg and 720
mg/kg enzyme complex supplemented to the control diet, respectively.
Enzyme complex :
The enzyme complex contained mainly neutral protease (3,000 U/g), acid
protease (3,000 U/g), endoamylase (500,000 U/g) and xylanase (65,000
U/g). It also contained lower amounts of exoamylase, β-glucanase,
pectinase, cellulase and cellobiase.
Study 3

38. Effect of EE on GIT traits & Blood
metabolites
The birds fed the diets supplemented with 180 mg/kg and 360 mg/kg
enzyme complex had better performance and nutrient availability, the
activities of amylase and trypsin in the digestive tract in the two
treatments were improved, the villus height and surface area of villus in
the small intestine increased and the crypt depth and epithelial thickness
of small intestine decreased.
Relative weights of pancreas and relative weights and lengths of small
intestine decreased.
Results:
Surface are of villus: VW/2×VL×2π

42. Blood Metabolites
Friesen et al. (1992) found that enzyme complex increased the digestion
rate of starch, while the product of starch digestion was absorbed into
blood in the form of glucose and so increased blood sugar content.
Borg et al. (1987) reported that blood urea nitrogen could accurately
reflect the state of protein metabolism and balance of amino acids, and
urea nitrogen was low when the balance of amino acids was good.
About Blood sugar & Blood Urea
nitrogen

43. Conclusion
The biggest single expense in any system of poultry production is
feed accounting for up to 70% of total production cost per bird.
Poultry naturally produces enzymes to aid the digestion of feed
nutrients. However, they do not have enzyme to break down fibre
completely and need exogenous enzymes in feed to aid digestion.
Consequently exogenous enzymes are a very useful tool in the
improving of physiological and metabolic mechanisms in GIT
espacially in NSP-based diets.