CHAPTER VII 



CONDITIONS AFFECTING THE DIGESTIBILITY OF 

 FEEDING STUFFS 



WE have already shown the effect of advanced stages of develop- 

 ment of plants on their digestibility. Some other factors that 

 influence the digestibility of feeding stuffs will now be considered. 



Different Classes of Farm Animals. As might be expected 

 from the differences in the digestive apparatus of the various classes 

 of farm animals, these differ somewhat in their ability to digest cer- 

 tain feeding stuffs. Concentrated feeds are digested to a similar 

 extent by nearly all classes of farm animals, but this does not hold 

 true in the case of coarse feeds. The digestion coefficients for meadow 

 hay and oat straw obtained by Kellner in the case of steers and 

 sheep will illustrate the differences met with. 1 



Digestibility of Hay and Straw by Steers and Sheep, in Per Cent 



Hay or straw of the same origin was fed to both classes of ani- 

 mals in these experiments. Greater differences are likely to occur 

 where digestion coefficients of feeds of different origin are compared. 

 Steers can, in general, digest bulky, coarse feeds better than sheep 

 can, while with easily digested feeds only minor differences occur in 

 the digestion coefficients obtained with these classes of farm animals. 



Horses and other non-ruminants have a lower digestive capacity 

 for coarse feeds than the ruminants. This is especially true as 

 regards the fiber content of feeds. Through their more thorough 

 mastication of roughage, and the fact that the feed is prepared for 

 digestion by being softened in the paunch previous to the stomach 

 digestion, the ruminants are able to better utilize the energy of the 

 fiber in coarse feeds, like hay and straw, than are horses or pigs. 

 The following average figures for digestibility of timothy, alfalfa 



Experiment Station Record 9, p. 509. 



63 



