240 



PRODUCTIVE FEEDING OF FARM ANIMALS 



according to Wolff-Lehmann and Armsby are given at the begin- 

 ning of this chapter. The former standards have been modified 

 by Haecker, 15 who has calculated the amounts of digestible protein, 

 carbohydrates, and fat required for the production of a pound of 

 milk testing 3 to 6.5 per cent as follows : 



Requirements for Milk of Different Richness 



Digestible 



* Given separately in Haecker's standards. 



In addition to giving digestible protein, carbohydrates, and fat 

 to the third decimal place, Haecker calculates the requirements 

 per pound of milk for differences in fat contents of only 0.1 

 of 1 per cent between 3.0 and 6.5 per cent. In view of the 

 great differences in the returns made by different cows from the 

 feed eaten, and the great variations to which feeding stuffs are 

 subject, both as regards composition and digestibility, it would 

 seem rather unnecessary to make such fine distinctions. Eckles 16 

 has modified the Armsby standards according to the fat content 

 of the milk produced, allowing 0.05 to 0.07 pound digestible pro- 

 tein and 0.26 to 0.45 therm per pound of milk testing 3 to 6 per 

 cent (p. 39). 



The American Practical Feeding Ration. The author pub- 

 lished in the nineties the following so-called " American Practical 

 Feeding Ration " for dairy cows, as a result of studies of the methods 

 of feeding and the experiences of more than one hundred promi- 

 nent American dairy farmers with regard to the amounts and 

 character of the feed which will be likely to give the best and most 

 economical results under our conditions when fed to good dairy 

 cows in full flow of milk and of an average weight of 1000 pounds : 17 



15 Minnesota Bulletin 130. 

 "Missouri Research Bulletin 7. 

 17 Wisconsin Bulletin 38. 



