MILK PRODUCTION 521 



TABLE 148. ESTIMATED REQUIREMENTS FOR MILK PRODUCTION 



616. The supply in the feed. Kellner states that ordinary 

 dairy rations will usually meet the requirements just stated and 

 that only in exceptional cases will it be necessary to supplement 

 the calcium supply. 



Forbes 1 has shown, however, that rations fully adequate, so 

 far as organic nutrients are concerned, to support a considerably 

 greater milk production than that on which Kellner 's require- 

 ments are based may nevertheless permit very material losses 

 of mineral ingredients, especially of calcium, magnesium and 

 phosphorus. Complete ash balances are reported for six 

 animals on three different rations, all of which maintained the 

 live weights of the cows and resulted in gains of body protein. 

 With an average live weight of about 935 pounds and an average 

 daily milk yield of about 36 pounds (16.38 Kgs.), the calcium 

 and phosphorus requirements as computed according to Kell- 

 ner's method and the actual amounts supplied in the rations 

 were : 



TABLE 149. CALCIUM AND PHOSPHORUS FOR MILK PRODUCTION 



1 Ohio Expt. Sta., Bui. 275 (1916). 



