ILLINOIS DAIRYMEN'S ASSOCIATION. 201 



leaves .9 of a pound of protein available for the production of -- pounds of 

 milk, and .9-Ml=.08+. Again a cow yielding 22 pounds of milk requires 

 2.5 pounds of digestible protein daily and she requires .7 of a pound for 

 maintenance there is left 1.8 for milk production, and 1.8-=-22=. 081-f, the 

 amount of protein required for one pound of milk according to Dr. Leh- 

 mann's revision of the Wolff standard for feeding dairy cows. 



While all the feeding standards have been very helpful to feeders, that 

 suggested by Dr. Lehmann seems to be a great improvement because it is 

 in a measure a guide in adjusting the ration to the needs of animals vary- 

 ing in productive capacity. Kuehn, a German scientist of great ability, 

 recognize the necessity of a feeding standard that was not confined to 

 such mathematical exactness as were those of Wolff, so he suggested a 

 standard that ranged in protein content from 1.5 to 2.4 pounds, but it does 

 not appear that he indicated when the minimum or the maximum was 

 required. 



During the months of February and March, 1895, an experiment was 

 conducted at this station, comparing timotry with prairie hay in which all 

 foodstuffs were subjected to chemical analysis and each ration was 

 weighed and each milking weighed and tested separately for butter fat 

 with the Babcock test, a complete record of which was published in bulle- 

 tin 67 of this station, pages 356-378. The following table gives the dry 

 matter and the digestible nutrients consumed daily and the milk and 

 butter fat produced during one of the periods in the trial. 



The data so obtained, incidentally revealed that the protein required 

 by cows in milk production was less than the amount prescribed by any 

 of the foregoing standards. 



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