THE DIGESTIBILITY OF FEEDINGSTUFFS 67 



stuff. As a rule, cattle digest the straws and coarse hays 

 better than sheep, but with hays of good quahty there is 

 no difference. Cattle and sheep digest roughages more 

 completely than does the horse, while the latter digests 

 them much more thoroughly than the hog. The reason 

 for this Hes in the special provisions in the digestive tracts 

 of ruminants and horses for the handUng of roughage. 

 On the other hand, the four classes of farm animals digest 

 concentrates equally well. 



Breed of Animal. — Different breeds of the same species 

 of animal possess an equal digestive power. Thus Armsby 

 and Fries ^ found that a pur^-bred Angus steer and a scrub 

 steer of predominant dairy typ^, digested the same ration 

 equally well. 



Age of Animal. — Within reasonable hmits the age of the 

 animal does not influence the digestibihty of the ration. Very 

 young animals mthout teeth and very old animals with 

 defective teeth of course would not be able to digest certain 

 rations very thoroughly. Also until the rumen or paunch 

 of the young ruminants is fully developed, the coarser part 

 of the ration will not be digested thoroughly. Armsby and 

 Fries ^ in experiments with two steers found but Httle 

 difference in their digestibihty as yearlings, as two-year-olds, 

 and as three-year-olds. 



The condition of the animal has no effect upon its power 

 of digestion. In the experiment by Armsby and Fries, 

 already quoted, it was found that a eer in good condition 

 and one in poor condition digested the same ration equally 

 well. 



Work by the Animal. — It often has been assumed that a 



1 U. S. Dept. of Agr. Buteav of Amin. Indus. Bui. 128. 2 {Ihid.) 



