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

KELLNER'S STARCH EQUIVALENT

• The classical method developed by Kellner in 1907 in Germany is a net energy system, since the production value of feeds is measured by their utilization for fat deposition in adult animals relative to the fat producing power of 1 kg of starch.
• Kellner’s system was based on the determination of carbon nitrogen balance by respiration experiments.

Definition:

• SE is defined as the number of Kg of starch that produces the same amount of fat as 100 kg of the respective feed.
• This value is also called as starch value of the feedstuff.

SE = ( Weight of fat stored per unit of food/ Weight of fat stored per unit weight of starch) X 100.

• One kg of starch fed in excess of maintenance requirement produced 248 g of body fat or since 1 gram of fat is equivalent to 9.5 Kcal, the NE value of 1 kg of starch for fattening is 2360 Kcal (2.36 Mcal).
• Kellner expressed the energy value of feedstuff by its fat producing ability relative to that of pure starch.
• (Eg.) When we say that the SE of wheat bran is 45, it means that 100 kg of wheat bran can produce as much animal fat as 45 kg of pure starch when fed in addition to maintenance ration or in other words 100 kg of wheat bran contains as much net/productive energy as 45 kg of the starch.
• Starch value of typical feedstuffs has been determined by carbon-nitrogen balance experiments.
• For rationing diets, starch values are computed from their content in digestible nutrients.
• Kellner determined the actual fat producing power of isolated nutrients typical of the proximate constituents of feedstuffs and the results are summarized in the table below.

Digestible nutrients	Fat deposited (g)	Starch equivalent factor
Starch	250	250		=1.0
		250
Crude fibre	250	250		=1.0
		250
Ether extract
From oil seeds	600	600	=2.4
		250
From cereals	525	525	=2.1
		250
From roughages	474	474	=1.9
		250
Protein	235	235	=0.9
		250

• It appears from the table that the starch values of starch, crude fibre and NFE are equal.
• The fat producing power of protein is lower, since breakdown of protein to nitrogen free substances and formation and excretion of urea need energy.
• The fat producing power of ether extract from oil seeds is considerably higher than that from cereals and roughages because the latter fractions contain a greater percentage of non-glyceride compounds such as waxes and pigments than the pure fat from oil seeds.