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

PHYSIOLOGICAL FUEL VALUE

• Based on the composition of carbohydrate, fat and protein the heat of combustion of the feed sample can be worked out using appropriate factors.
• From the gross chemical composition of the feed samples the amount of energy yielding nutrients namely carbohydrate, fat and protein are estimated.
• If the amount of each is known it is easy to workout the heat of combustion of the feed sample using appropriate factors.
• The heat of combustion of individual carbohydrates, proteins and fats differ with their composition. (Eg.) As determined by Atwater GE of sucrose is 3.96 Kcal/gram and that of starch is 4.23 Kcal/gram.
• Energy yield of butterfat was found to be 9.21 Kcal/gram and that of lard, 9.48 Kcal/gram.
• For practical use individual figures were averaged to apply to the major food stuffs (carbohydrate, fat and protein) as gross energy of food.