The Constant increase in the price of feed ingredients is a major constraint in most developing countries, as a result, cheap and non-conventional feed ingredients are used, which contain a higher percentage of Non-starch polysaccharides (NSPs). Today the poultry industry uses different heat-stable enzymes in pelleted feeds as a solution that degrade crude fiber, starch, proteins, fat, and phytate to improve the use of other nutrients and to have more feed efficiency.
Anti-nutritional factors, crude fiber, and variable NSPs of cereals cause obstacles in the digestive system. This is because animals are unable to produce the necessary enzymes to break down these compounds.
Some of the NSPs are soluble in water and form a viscous gel-like composition in the intestine, thus reducing the function of the digestive system.
Mainly water-soluble and viscous Arabinoxylans belonging to the pentosans group which causes high viscosity in the content of the digestive tract are assumed to be the main responsible for this action. Also, it leads to increased water consumption and as a result sticky excreta.
The proportion of gross energy lost via excreta is approximately 30%, that is to say, about 70% of the gross energy of a common diet fed to poultry is metabolized. So use of enzyme is a solution to add to the standard poultry diet particularly diets based on wheat and barley.
Industrial exploitation of microbial enzymes in Western countries started 100 years ago with the discovery of the production process of alpha-amylase from Aspergillus fungus.
Microorganisms that are generally involved in the production of enzymes include bacteria (Bacillus subtilis), Fungi (Aspergillus, Trichoderma), and yeasts (Saccharomyces cerevisiae).
Type of enzymes available in the poultry industry:
Xylanase, Beta-gluconase, galactosidase, phytase, Multi-enzyme, cellulose (B-gluconase), Protease, and lipase.
The benefits of enzymes in poultry diets:
- Reducing the viscosity of digestible materials
- Increasing digestion and absorption of nutrients, especially fat and protein
- Improving apparent metabolizable energy value (AME)
- Increase feed intake
- Increase body weight
- Reducing the adhesion the beak and anus
- Changes in the population of microorganisms in the digestive tract
- Reduction in water consumption
- Reducing the amount of water in the excreta
- Reduction of ammonia production from feces
- Decrease nitrogen and phosphorus excretion
- Increase in energy availability
- A wide range of feed ingredients is used and leads to a reduction in the cost of feed formulation
- Prevention of coccidiosis problems
- Reducing the moisture content of feces and litter and decreasing the contamination of eggshells
- Increased egg production and egg weight
- Reducing the excretion of organic phosphorus in the environment by using phytase enzyme to reduce the inorganic phosphorus required in the diet and prevent the accumulation of water in the environment
- Increased digestibility by breaking down NSPs into smaller polymers and eliminating their ability to create viscosity of digestible materials and increasing the digestibility of nutrients.
- Breaking the bond between phosphorus and the myo-inositol ring of phytic acid, the phytase enzyme releases phosphorus from minerals, amino acids, and starch fibers attached to phytate phosphorus, and in this way , indigestible phytate phosphorus is converted into digestible phosphorus.
Factors affecting the benefits of enzymes:
- Type and amount of cereals in the diet
- Levels of anti-nutritional factors in cereals
- The spectrum and concentration of the used enzymes
- Type and age of animals
- Type of intestinal microflora and physiology
-By Dr. Nader Rangsaz
