Question

Which among the following enzymes is used as feed additive for degrading structural polysaccharides in poultry ration?

• A. Phytase
• B. Protease
• C. \(\beta\)-glucanase
• D. Lipase

Hint:

Remember that \(\beta\)-glucans and arabinoxylans are the main non-starch polysaccharides (NSPs) in grain. Adding \(\beta\)-glucanase or xylanase is the standard way to reduce gut viscosity in poultry fed barley or wheat-based diets.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Poultry do not naturally produce enzymes capable of digesting non-starch structural polysaccharides (NSPs) present in the cell walls of cereal grains.
Exogenous enzymes are added to poultry feed to break down these indigestible structural carbohydrates.

Step 2: Detailed Explanation:
Cereal grains like barley, oats, and rye contain high levels of soluble non-starch structural polysaccharides, particularly \(\beta\)-glucans.
These soluble \(\beta\)-glucans are not digested by the bird's own enzymes.
Instead, they absorb water in the digestive tract and form a highly viscous, gel-like substance.
This high viscosity slows down the passage of digesta and interferes with the digestion and absorption of other nutrients.
It also leads to sticky droppings, which cause wet litter issues in poultry houses.
Adding the exogenous enzyme \(\beta\)-glucanase breaks down the complex \(\beta\)-glucan chains into smaller, non-viscous sugars.
This reduces intestinal viscosity, improves nutrient digestibility, and prevents wet litter problems.
Phytase is used to release bound phosphorus from phytate.
Protease degrades proteins, and lipase digests fats, neither of which are structural polysaccharides.

Step 3: Final Answer:
\(\beta\)-glucanase is the enzyme used to degrade structural polysaccharides in poultry diets.