72 PRINCIPLES OF FEEDING FARM ANIMALS 



oats, and wheat, whicli are grown primarily for their yecd8, 

 should be allowed to mature before harvesting. 



Curing and Storage of Feeds. — The euring of feeds, if 

 properly done, has no effect upon their digestibihty. If 

 improperly done, it may decrease the digestibilit}-. Thus, 

 exposure to rains leaches out a large part of the soluble and 

 more digestible matter of the feed. Also, the digestibihty 

 of hay may be decreased by the loss of the leaves, which 

 are the most digestible part of the roughages. Heating 

 of hay in the mow or stack materially decreases the 

 digestibihty, as the more digestible portions of the plant 

 are most subject to fermentation. The digestibihty of 

 hay may be decreased slightly by storage from one year 

 to the next. 



Amounts of Feed. — In recent investigations ^\^th cattle 

 at the Ilhnois Experiment Station,^ by Mumford, Grindley, 

 Hall, Emmett, Joseph, and Allison, it was found that when a 

 large proportion of concentrates to roughage was fed (5 

 parts of the former to 1 part of the latter), the amount of 

 feed consumed had little or no influence upon the digestibility 

 of the ration. However, when the proportion of concentrates 

 in the ration was smaller (3 parts of concentrates to 1 part 

 of roughage, and 1 part of concentrates to 1 part of roughage), 

 the digestibility^ of the ration varied inversely with the amount 

 of feed consumed. Maintenance rations were digested most 

 thoroughly, ^-ith one-third feed, two-thirds feed, and full- 

 feed rations ranking in the order named. Thus the coef- 

 ficients of digestibihty of the dry substance for the different 

 lots were as follows : 



> Bui. 172. 



