CO Report of Department of Animal Husbandry of the 



this demand in a given case. For instance, during her maximum 

 production the millv of Cow 12 contained about 1.12 lbs. of pro- 

 tein (N X 6.25) daily. The cow was eating each day 2.6 lbs. of 

 digestible protein. The real question is, What is the function 

 of the protein remaining after deducting the milk protein from 

 the total amount eaten, or in this case, 1.48 lbs.? An examina- 

 tion of the figures for urine nitrogen shows that the larger part 

 of this balance, or 1.2 lbs., was not stored but was broken down 

 into simpler compounds and so destroyed. Does this metabolic 

 change bear any fixed relation to the milk solids or milk fat 

 secreted? The data of these experiments indicate a negative 

 answer to this question. 



