ANN 111: Principles of Animal Nutrition and Feed Technology (2+1)

FACTORS AFFECTING TDN VALUE OF FEED

• % Dry matter:
• In high moisture feed the nutrient concentration is less and so the TDN value on fresh matter basis will be less.
• % Digestibility of dry matter:
• The presence of indigestible substances like lignin, acid insoluble ash will interfere the digestibility of other useful nutrients.
• Hence feeds with high lignin and/or acid insoluble ash will have low TDN values.
• Presence of minerals:
• Since minerals as such contribute no energy, high mineral containing feeds will have low TDN.
• % Digestible fat in the feeds:
• The feeds containing high digestible fat will have high TDN value because due weightage is given for its high energy content in TDN system.
• For feeds containing more digestible fat the TDN value sometime exceeds 100%.