74 



PRINCIPLES OF FEEDING FARM ANIMALS 



Addition of Nitrogenous Nutrients. — The increase of the 

 protein in a ration causes not only no depression of digesti- 

 bility but, as just stated, it may increase the digestibility of 

 the carbohydrates if there is an excess of them in the ration. 

 Moreover, it seems from experiments at the Ilhnois Experiment 

 Station that the addition of protein increases the digestibility 

 of the entire ration. In an experiment by Mumford, Grind- 

 ley, Hall, Emmett, Joseph, and AUison,^ eight steers were 

 fed a ration consisting of hay 1 part, and corn 5 parts. 

 Then one part of the corn was removed and an equal amount 

 of linseed meal (a feed containing about 34 per cent of pro- 

 tein) was substituted for it. The average coefficients of 

 digestibility upon these two rations were as follows : 



The same thing, though in less degree, is indicated by ex- 

 periments with hogs at the Ilhnois Station ^ by Dietrich 

 and Grindley. 



Digestible Nutrients in Feedingstufifs. — The practical 

 stock feeder is not especially interested in the coefficients of 

 digestibihty of feedingstuffs nor in the chemical composition 

 of feedingstuffs, provided he knows their content of digestible 

 nutrients. Knowing the chemical composition of a feed and 

 knowing its coefficients of digestibility, it is an easy matter to 

 calculate the amounts of digestible nutrients in the feed. 

 1 lU. Agr. Exp, Sta. Bui. 172. 2 BuI. 170. 



