CONDITIONS INFLUENCING DIGESTION 133 



matter of the ration was largely increased and the pro- 

 tein remained constant or was diminished. However, 

 the depression of the digestibility of the crude fiber is 

 not easily explained on any other ground than that of 

 the influence of the greater proportion of starch. 



What is claimed as the effect of a disproportionate 

 addition to the supply of carbohydrates does not appear 

 to be true of a similar increase in the ration of fat and 

 easily digested protein. Several experiments in which 

 oils and albuminoids have been added freely to a basal 

 ration did not indicate that such addition had any mate- 

 rial effect upon digestibility. 



194. Influence of work. Such evidence as has been 

 secured with both man and farm animal indicates that 

 even severe labor has no material influence upon diges- 

 tion one way or the other. Scheunert's work with horses 

 leads him to conclude, however, that exercise improves 

 digestion. 



195. Influence of species, breed, age, and individual- 

 ity. The conclusion reached by the early experimenters 

 in the field of animal nutrition that the digestive efficiency 

 of the several species of ruminants was practically uni- 

 form has not been set aside by more recent observations. 

 The number of experiments upon which this conclusion 

 was based was large, and their verdict is not likely to be 

 reversed by observations less extensive or less complete. 



The following coefficients were obtained from German 

 trials with meadow hay : 



DRY SUBSTANCE DIGESTED FROM MEADOW HAT (PER CENT) 



Samples Best Medium Poor 



Sheep . 42 67 61 55 



Oxen 10 67 64 56 



Horse 18 58 50 46 



