292 The Feeding of Animals 



particular animal, and the non-nitrogenous nutrients 

 should be present in sufficient quantity to protect the 

 protein that it may be applied to its peculiar uses 

 rather than be consumed for heat production. It 

 is more than probable, though, that the nutritive ratio 

 may vary considerably from the German standards 

 without causing any appreciable influence upon growth, 

 work or milk yield. 



We have good reasons for believing, however, that 

 when the supply of food meets the requirements of 

 the animal as to quantity, the nutritive ratios 

 given in the feeding standards provide fully for the 

 needs of animals under all conditions. The signifi- 

 cant fact is that in practice it is possible to depart 

 so widely from these ratios as to greatly diminish the 

 efficiency of the ration for specific purposes, and this 

 is the justification of standards which may only ap- 

 proximate to the best, but which serve admirably as 

 a guide in avoiding serious errors. The foregoing 

 statements do not mean that the feeding formulas so 

 far published are the result of guess-work and rest 

 upon no basis of exact observations, for this is not true. 

 It is simply intended to point out the fact that we can- 

 not now set exact limits to the formulas of nutrition. 



4. The rations should be compounded with refer- 

 ence to the quality of the product. Our knowledge 

 of the influence of foods upon the quality of meat 

 products is indefinite, but that food has an influence 

 upon the flavor of milk and upon the chemical and 

 physical properties of butter, seems to be fairly well 

 established. 



