408 FUNDAMENTALS OF AGRICULTURE. 



digestibility of feeds. The chemist has already 

 worked out these for us, and he expresses the compo- 

 sition as follows: 



COMPOSITION OF CORN (GRAIN) IN PER CENT. 

 Protein Fat Nitrogen Free Extract Fiber Water Ash 



10.3 5-0 70.4 2.2 10.6 1.5 



The above analysis is very simply translated. It 

 means that in every 100 Ibs. of corn grain, there are 



10.3 Ibs. of protein, 5.0 Ibs. of fat, 70.4 Ibs. of nitrogen 

 free extract, 2.2 Ibs. of fiber, 10.6 Ibs. of water and 

 1.5 Ibs. of ash. Or there are 10.6 Ibs. of water and 



89.4 Ibs. of dry matter. 



Digestibility of Feeds, Knowing the composition 

 of feeds, it is now necessary to become acquainted with 

 the actual amounts of the nutrients (protein, fat, ni- 

 trogen free extract and fiber) that the animal can 

 assimilate or digest. When food is eaten by the 

 animal it is not all digested. Part of it is excreted 

 as manure. This latter part, or that which is excreted, 

 is indigestible. We can mention the digestibility of 

 the above sample of corn grain, which composition is 

 given, for an example. 



DIGESTIBILITY OF CORN IN PER CENT. 



Protein Fat Nitrogen Free Extract Fiber 

 76 86 93 58 



That is, in 100 Ibs. of the grain of corn, 76 per cent, 

 of the 10.3 Ibs. of protein is digestible, 86 per cent, of 

 the 5 Ibs. of fat is digestible, 93 per cent, of the 70.4 

 Ibs, of nitrogen free extract is digestible, and ^8 per 

 cent, of the 2.2 Ibs. of fiber is digestible. We can 

 represent this in another way by stating the total 

 pounds of digestible ingredients in 100 Ibs. of corn 

 grain. 



TOTAL POUNDS DIGESTIBLE NUTRIENTS IN 100 



POUNDS OF CORN GRAIN 



Protein Fat Nitrogen Free Extract Fiber 



7-8 4-3 65.5 1.3 



