MILK PRODUCTION 



The experiments by Haecker and by Woll on herds (602) 

 seem to justify the conclusion that in commercial milk produc- 

 tion in the United States a ration supplying, in addition to the 

 maintenance requirement, digestible protein equal to 150 to 

 1 60 per cent of the milk protein yielded is ample in this respect 

 to sustain a normal rate of milk production and may be dis- 

 tinctly more profitable than a ration richer in protein. It is 

 not impossible, however, that when circumstances warrant 

 the effort to secure the maximum production possible to the 

 animal a more liberal supply of protein would be advantageous. 



Energy requirements for milk production 



604. Energy content of milk. As in other forms of stock 

 feeding, the principal factor in determining the energy required 

 in the feed is the amount of chemical energy contained in a 

 unit of product. In the case of milk production this factor 

 varies through a wide range on account of the large differences 

 in composition of milk due to individual and breed differences, 

 stage of lactation, etc. 



Haecker 1 has arranged the results of analyses of 543 samples 

 of milk in ten groups according to the fat content. His averages, 

 together with the energy content per pound of milk as computed 

 by the writer, are as shown in the following table : 



TABLE 144. COMPOSITION AND ENERGY VALUE OF MILK 



Minn. Expt. Sta., Bui. 140, p. 51. 



