Applied Animal Nutrition-I

ENERGY REQUIREMENT BY FEEDING TRIALS

• The value may be expressed in terms of TDN by inclusion of a digestion trial or may be calculated from the average digestion coefficients.
• The inclusion of metabolic trial helps to calculate the results in terms of ME.
• As live weight is the sole criterion of exactness of this method, it should be noted that the weight should remain constant over an extended period for direct application into practice.
• If for any reason there be gain in weight or loss, necessary correction in intake should accordingly be made for such loss or gain in weight. Correction figures are shown below:

Pounds gained x 3.53 = TDN required for gain

Pounds lost x 2.73 = TDN equivalent to loss.

• Such corrections are, however, only approximate since the nature of tissue gained or lost is difficult to assess, eg., if the accumulation of water, which has no feed equivalent, be responsible for weight gain, then the use of the above correction factor form gain will be meaningless.
• The object, therefore, is to use these correction factors as minimum as possible.
• Another defect of this method is that consistency of weight does not necessarily mean the integrity of body tissue or in other words the weight maintenance does not mean the energy maintenance.
• This defect, however, can be eliminated by inclusion of slaughter test, which, however, adds to the cost of experiment and at the same time may not be practicable for all classes of livestock.