lull. 



PUBLIC DOCOIENT — Xo. ;51. 



109 



of this extra })rotein may be clearly seen in maiiUaiiiiiig' the 

 flow of milk. It would be of interest to know whether it would 

 have maintained its inflneiiee throughout the entire milking 

 l)eriod. The herd receiving the shortage of protein was obliged 

 to adjust itself to the low-protein diet. It was able to increase 

 somewhat in live weight (fat-^), but its milk flow was of 

 necessity noticeably checked. It is quite probable that some 

 cows of pronounced ability as milkers would not shrink as 

 rapidly as others on a low-protein diet, but for a time would 

 have taken the needed protein from that stored in the body. 



Effect of Protein on Average Composition of the Milk {Per Cent.). 



The above average figures were secured by taking the average 

 of the weekly analysis of the milk produced by each cow and 

 multiplying it by the pounds of milk j^roduced, the result being 

 the pounds of the several ingredients produced by each cow. 

 These were addeil, and gave the total milk and milk ingredi- 

 ents produced by each herd. The total ingredients divided by 

 the total milk produced ga\e the average j)ercentages. The 

 fact that the milk produced by each herd did not show the same 

 composition in the preliminary period prevents a direct com- 

 parison. It will be observed, however, that in case of Herd I. 

 the milk in the second period changed but little in composition 

 from that produced in the first period, the principal difference 

 being a slight increase in the fat, due evidently to the ad- 

 vance in lactation. Herd II. produced milk also with only 

 slight variations in the two periods. The fat increased .36 of 1 



