MILK PRODUCTION 



59 



The protein content of the milk from the low protein groups 

 is not reported, but an approximate estimate indicates that it 

 could not have been much less than the surplus of feed protein 

 over maintenance, thus furnishing further instances of an ap- 

 parently high percentage utilization of feed protein (586). 

 While the indications are that such very low protein rations 

 were inadequate, it seems clear that a surplus of 40 or 50 per 

 cent of available protein over that contained in the milk was 

 ample to support normal production. 



Woll 1 has reported a nine-year series of observations on the 

 dairy herd of the Wisconsin Station, the time being divided into 

 three periods of three years each, during the first and third of 

 which the rations had a nutritive ratio of 1:7, while during the 

 second three years it was i : 6. The estimated digestible pro- 

 tein consumed per day by cows weighing slightly over 1000 

 pounds was 



Average of periods A and C 1.76 pounds. 

 Average of period B 1.97 pounds. 



TABLE 143. SURPLUS or AVAILABLE PROTEIN IN HERD RATIONS 



VVis. Expt. Sta., Research Bui. 13. 



