DIGESTION BY RUMINANTS 143 



Experiments have been made with oxen, cows, 

 sheep and goats. The power of these different 

 animals for digesting food is apparently very similar, 

 but no accurate comparisons have as yet been made. 

 The table (p. 144) shows the average results obtained 

 with ruminating animals fed on the foods respectively 

 mentioned. The figures given express the " digestion 

 coefiicients " found for each constituent of the food 

 consumed. 



The digestibility of the foods in the upper division 

 of the table has been for the most part determined 

 by feeding animals on these foods alone. The digesti- 

 bility of the foods in the lower division of the table 

 has been found by supplying them in various propor- 

 tions along with hay, the digestibility of which had 

 been already ascertained with the same animal. 



In the case of ordinary meadow and clover hay, the 

 total organic matter digested is but 55 — 60 per cent, 

 of that supplied ; with hay of exceptional quality the 

 proportion digested may rise to 70 per cent. With 

 straw only about 45 — 55 per cent, of the organic 

 matter is digested, the minimum occurring with wheat 

 straw. 



The digestibility of the nitrogenous matter in hay 

 and straw increases as its proportion rises. A sample 

 of wheat straw experimented with contained 4'8 per 

 cent, of nitrogenous matter in its dry substance, of 

 which only one-fifth, or 20 per cent., was digested; 

 while good lucerne hay, with 19 "3 per cent, of nitro- 

 genous matter, had 76 per cent, of this in a digestible 

 form. This general fact is shown by digestion experi- 

 ments made in the laboratory with pepsin and trypsin 

 solutions, as well as by experiments with an animal ; 



