THE NUTRIENTS AND DIGESTION 327 



while in animal products it is surrounded by the more easily 

 digested fat. 



Concentrated Feeds. — ^Poultry are able to digest little of the 

 bulky feeds, such as the cured hays and fodders. The con- 

 centrates, such as grains and their by-products, they digest 

 with a fair efficiency. It is possible, however, to secure a 

 feed of so great a concentration that the digestive tract will 

 become disarranged and fail to carry on the work of diges- 

 tion properly, in which case the digestive coefficient would 

 undoubtedly be lowered. 



Cochel and Jacksoii^ found that rations carrying 3.5 per 

 ceijt. of total weight in crude fiber seemed to give better 

 results for laying hens than those with a higher or lower 

 per cent., and it is reasonable to suppose that at least a 

 part of the value of the fiber is to be found in its opening 

 up the ration so that the digestive juices may act more 

 readily and thoroughly. 



Palatability. — ^Experimental evidence showing that palata- 

 bility in and of itself increases the digestive coefficient of 

 feeds is lacking. It is popularly supposed to be the case, 

 however, and the supposition does no harm. As Brown^ 

 ppints out in discussing the comparative digestibility of 

 oats and corn, palatability and good digestibility are likely 

 to go together. Bartlett' calls attention to the fact that of 

 two mixtures he was feeding in digestion trials, the mixture 

 which was the least palatable was also the lowest in 

 digestibility. 



Cooking and Wetting Feed. — ^The cooking and wetting of 

 feeds have little if any effect upon their digestibility, directly, 

 though either may increase the palatability of a ration. 



Rice* found as a result of a year's test with forty Single 

 Comb White Leghorn pullets, to twenty of which the ground 

 or mash portion of the ration was fed wet and to twenty it 

 was hopper fed dry, that the dry mash gave better results 

 in gain in weight, production of eggs, gain in weight of eggs, 

 hatching power of eggs, days lost in moulting, mortality 



' Pennsylvania Bulletin No. 120. 



' Bureau of Animal Industry, Bulletin No. 56. 



s Maine Bulletin No. 184. ' Cornell Bulletin No. 249. 



