DIGESTION AND NUTRITION 339 



nation of digestion coefficients have not been perfected 

 and a number of sources of minor error are introduced in 

 digestion experiments. In the case of the feces, the 

 ether extract contains bile, nitrogen, cleavage products, 

 and a number of other non-fatty compounds. Hence the 

 figures for the digestibility of the ether extract are in- 

 variably too low. Not all of the nitrogen of the feces is 

 in indigestible forms, hence there is a tendency for the 

 digestibility of the crude protein to be too low, then too, 

 it is difficult to assign an absolute nitrogen factor for the 

 determination of the crude protein. Notwithstanding 

 these known imperfections in determining the digestibility 

 of the food, the general results are of great value to the 

 farmer as they indicate ways by which the largest re- 

 turns, due to the highest degree of digestibility, can be 

 secured. Some of the digestion coefficients of the more 

 common food materials are given in the following table 

 which is taken from Bulletin No. 77, U. S. Department 

 of Agriculture, Office of Experiment Stations : 

 DIGESTION COEFFICIENTS 



.3 & 

 g S -5 tf 



? P ? - 



& 



08 oS < UP. uc w 



Green Fodders. 



Timothy 63.5 65.6 32.2 48.1 55.6 65.7 53.1 



Dent corn 67.8 69.8 35.6 59.7 60.2 73.7 74.1 



Oats 59.5 60.9 53.4 71.8 52.8 62.6 69.2 



Red clover 66.1 68.1 55.0 67.0 52.6 77.6 64.5 



Silage. 



Dent corn silage 65.1 67.1 32.2 49.3 66.7 68.6 80.0 



Flint <( " 73.! 76.1 32.9 62.8 75.1 76.9 81.8 



