Home Measure of Nutrient Content in feed
Print E-mail

Measure of Nutrient Content in feed

Energy measurements


Energy is produced in the animal body from simple sugars and fatty acids. Energy is utilized for maintaining body temperature, all cellular and muscular activity, biosynthesis of various molecules, milk production.

Feed energy is measured in terms of total digestible nutrient (TDN). It is based upon the assumed equivalence of carbohydrate and protein as energy sources, and the higher energy content of fat (ether extract).The formula for percentage TDN of a feed is: TDN, %=  digestible crude protein, %+ digestible NFE , %+ digestible crude fiber, % + 2.25 x digestible ether extract,%. The NFE is the nitrogen free extract, corresponding to readily digestible carbohydrates. The ether extract is multiplied by 2.25 to make it carbohydrates equivalent (i.e. 9 kcal /g divided by 4 kcal/g=2.25).

Units for expressing nutrient requirements

  • Energy requirement of buffalo is expressed as TDN, g or Kg per day.
  • Protein requirement is expressed in term of CP or DCP, g or Kg per day and also in term of RDP and UDP, g or Kg per day.
  • Requirements of minerals are expressed as % (g per 100g feed dry matter intake) or ppm (parts per million or mg per Kg dry matter intake).
  • Vitamin requirements are expressed as IU (international unit) or mg per Kg dry matter intake or per animal per day.