SECTION XXVII. 



STANDARDS FOR MILCH COWS. 



Wolff's standard for milch cows, which has been generally 

 used, has been found to be unsatisfactory for American feeders. 

 Many investigations have been conducted to determine the re- 

 quirements for milch cows m this country. 



Adjust the Ration to the Cow's Needs. — Haecker in Minnesota 

 Bui. 79, says : "It has long since been recognized that because 

 of the difference in composition of the various kinds of feed 

 stuffs no single standard of composition for all feeds would be 

 practical, and yet, while there is as great a difference in the 

 composition of milks as there is in feed stuffs, there has been no 

 adjustment of the nutrients in the ration to the quantity and 

 character of the solids contained in the milk yielded, though 

 such an adjustment is simple and practicable. If in formulating 

 a ration it is deemed necessary in economic milk production, to 

 take note of the fact that one feed stuff contains 12 per cent, 

 protein and another 20 per cent., is it not equally important in 

 our attempt to adjust the ration to the needs of the cow in milk 

 production to also take into account the fact that one cow may 

 give milk containing 3 per cent, fat while that of another may 

 contain twice as much? It would seem quite as consistent to 

 feed an animal food regardless of its composition as to feed an 

 assumed balanced ration regardless of the composition of the 

 product which is to be elaborated from the nutrients in the food. 



"Great stress has been placed upon the fact that the nutrients 

 in milk have a nutritive ratio of approximately one to five, and 

 that therefore the ration for a milch cow should have a similar 

 nutritive ratio; apparently overlooking the fact that only 50 per 

 cent, of the ration is used in milk production and the balance 

 for maintenance of body. If note is taken of the fact that 

 about half the ration is used for maintenance and that the main- 

 tenance ration has a nutritive ratio of one to ten, it becomes 

 apparent that for the production of milk of average quality by ■ 

 an animal of average milk producing powers the nutritive ratio 

 of the ration should be approximately i : 7.5. But since animals 



