RELATIVE VALUES OF FEEDING STUFFS 625 



amounts to greedy feeders or to animals with imperfect teeth, 

 more or less of it escapes mastication and, protected by the 

 outer coats, passes through the digestive tract relatively unacted 

 upon. Such apparently intact grains of corn, oats, etc., still 

 capable of germination, are a familiar sight in the droppings of 

 heavily fed animals. 



Such visible losses, however, are not confined to the feeding 

 of whole grain but, although less obvious, extend to cracked or 

 crushed grain as well. If, for example, the feces of full-fed 

 cattle receiving cracked com or other grain be washed out, a 

 considerable amount of fragments of grain may be recovered, 

 the amount depending upon the total quantity fed and the con- 

 sequent rapidity with which it passes through the digestive 

 tract. Moreover, it is evident that the mechanical separation 

 by washing is necessarily imperfect. Not only may the sieve 

 hold back other things than fragments of grain, but it is like- 

 wise clear that any undigested fragments of the latter which 

 are smaller than the meshes of the sieve will pass through and 

 be lost, so that fine meal or well-masticated grain might suffer 

 a greater loss through incomplete digestion than would be 

 indicated by such tests. While it is to be supposed that smaller 

 fragments will undergo more rapid solution in the digestive 

 tract than larger ones, it is evident that the rapidity of passage 

 through the organs is an important factor and that even com- 

 paratively small bits may, under some circumstances, escape 

 complete digestion, while on the other hand, with light feeding, 

 whole grain might be almost as well digested as when ground. 

 Qualitatively, the results reached by washing out the feces are 

 of great interest, but they may readily be misleading as regards 

 the actual advantage of grinding. 



Surprisingly few investigations upon the relative digesti- 

 bility of ground and unground grain have been reported. Jor- 

 dan and Hall, 1 in their compilation of American digestion ex- 

 periments up to 1900, present two comparisons with horses 

 and two with swine, all of which show the ground grain to be 

 more digestible than the unground, the difference with respect 

 to the dry matter ranging from 3.3 to 14 per cent. 



Gay, 2 in experiments upon oats with a horse weighing about 



1 U. S. Dept. Agr., Office Expt. Stas., Bui. 77, p. 97- 

 a Centbl. Agr. Chem., 25 (1896), 729. 



2 S 



