ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 



29 



the standard fixes 3.3 pounds as the amount required for 27.5 of ordinary 

 milk. We might take the records of the other mature cows in the herd 

 that were not making gain in weight, and show that either our cows or 

 the scientists are wrong, and where there is such a discrepancy between 

 the calculations of the scientist and the performance of the cows, I am 

 inclined to side with the cows. 



It is claimed that a cow requires .7 of a pound of protein daily for 

 body maintenance per thousand pounds live weight, and if this is cor- 

 rect—and I am inclined to the belief that it is — our records indicate that 

 after deducting the amount of protein needed daily for body mainten- 

 ance, the protein required to produce a pound of milk is as follows: 



M 



ilk containing 



2.5 per 



cent. 



fat. 



.035 of protein 





3. " 



" 





.039 " 





3.5 " 



" 





.043 " 





4. " 



" 





.047 " 





4.5 " 



" 





.051 " 





5. " 



(( 





.055 '• 





5.5 " 



" 





.059 " 





6. " 



a 



J' 



.063 " 



With such a standard all that is necessary to determine the amount 

 of jrotein needed by a cow, to maintain her flow, is to ascertain the 

 amount and quality of milk yielded daily and multiply the yield of milk 

 by the amount' of protein needed to produce a pound of milk of that qual- 

 ity, and add to this that needed for body maintenance. As an illustration, 

 let us suppose that a cow weighs 800 pounds and yields daily 20 pounds of 

 milk testing 4 per cent fat. She needs daily .58 of a pound of protein for 

 body maintenance and .047x20 equals .94 plus .56 equals 1.50 pounds of 

 protein required daily to maintain a body weighing 800 pounds, and pro- 

 ducing 20 pounds of 4 per cent milk. If she is giving milk testing 5 per 

 cent fat, she will need .055x20 equals 1.10 plus .56, or 1.66 pounds of pro- 

 tein. 



Again let us apply this standard to the cow Sweet Briar, that yielded 

 25.8 pounds of milk testing 5.3 per cent fat. She weighed 1060 pounds, and 

 required, therefore, .74 of a pound of protein daily for maintaining her 

 body. To produce a pound of milk testing 5.3 per cent fat requires .0574 



