FEEDS AND FEEDING 



they will produce a ration of i :5 or i :6. It 

 is best, therefore, to experiment a bit on paper 

 until one finds a combination that will approxi- 

 mate the standard as nearly as possible. 



The Wolf standard of feeding states that a 

 cow giving between twenty-two and twenty-five 

 pounds of milk per day requires 25 pounds of 

 dry matter, 2.6 pounds of protein, and 15.12 

 pounds of carbohydrates and fat together. 

 Here it is well to remind the reader that the 

 ratio of foods is not expressed in the terms of 

 the relative weights of different constituents 

 used, but in terms of the relative quantities of 

 energy yielded by them. Thus protein and 

 carbohydrates are about equal, weight for 

 weight, in energy-yielding power; but the aver- 

 age fat of feeds yields about two and one-fourth 

 times as much energy as an equal weight of 

 average carbohydrates. So as the nutritive 

 ratio of a ration is the ratio of the energy of its 

 digestible protein to the energy of its digestible 

 non-protein, it is equal to the ratio of the 

 weight of digestible protein to the weight 

 of digestible carbohydrates, plus 2^ times the 



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