MILK PRODUCTION 327 



important physiologically than keeping up the necessary 

 proportion of protein, though the former may be accom- 

 plished more easily than the latter because of the usual 

 character of home-raised crops. 



FEEDING STANDARDS FOB DAIRY COWS 



The feeding standards for dairy cows, which are 

 regarded as embodying our most advanced knowledge, 

 have been reached through several stages of development. 

 The following are brief descriptions of these stages with 

 suggestions as to their imperfections: 



426. Thaer's hay values. — ^Albrecht Thaer, known as 

 the father of scientific agriculture, more than a half-cen- 

 tury ago suggested "hay values" as the basis for express- 

 ing feeding standards. He calculated the relative values 

 of feeding-stuffs in terms of good meadow hay, the neces- 

 sary quantities of rations and substitutions of feeding- 

 stuffs in them to be based on such values. It is now per- 

 fectly understood how crude are such standards for they 

 ignore the varying digestibility of feeding-stuffs and the 

 necessary relations in the proportion of nutrients. Thaer 

 seems to have ignored weight and production as factors 

 in determining what a ration should be. 



427. Grouven's milk-feeding standards. — Grouven 

 later introduced the factor of weight, and formulated 

 eight standards for milch cows to be applied to animals 

 weighing from 772 to 1,543 pounds. The matter of vary- 

 ing production was ignored. The daily ration suggested 

 for cows weighing 1,000 pounds was not irrational, this 

 being: Dry matter 28.7 pounds, crude protein 2.76 pounds, 

 fat .86 pound, and carbohydrates 14.55 pounds, a ration 

 adequate to sustain a generous flow of milk. 



