Indirect method of determining the digestibility: Digestibility by difference.

INDIRECT METHOD OF DETERMINING DIGESTIBILITY : DIGESTIBILITY BY DIFFERENCE

Difference method

  • When the digestibility of poor quality non-maintenance type of forage like stovers, kadbi, straws or mature grasses is to be determined because these cannot be fed as sole source of nutrients.
  • If the digestibility of oilseed cakes, cereal grain and concentrate mixture is to be determined then difference method is followed since these cannot be fed as sole feed to ruminants.

Procedure

For example, if the digestibility of nutrients in a concentrate like maize grain or groundnut cake and in a poor quality roughage like straw is to be determined then three digestibility trials in a sequence are conducted.

  • 1st digestion trial
    • ¬†feed the animals with a good quality roughage like legume hay e.g. cowpea hay to determine the digestibility of nutrients in it.
  • 2nd digestion trial
    • the same animals are fed the same good quality fodder i.e. cowpea hay that was fed during first digestion trial along with known quantity of concentrate like groundnut cake or maize grain etc whose digestibility is to be estimated by difference.
  • 3rd digestion trial
    • by feeding the same animals with the concentrate whose digestibility was estimated in the second trial along with the poor quality roughage i.e. grass whose digestibility is to be determined. The digestibility of poor quality roughage will be determined by difference using predicted value of groundnut cake with the help of earlier trials (a) and (b).

Measure quantity of green fodder is given in digestion trial  Concentrate feed

Last modified: Friday, 30 March 2012, 9:55 AM