A STUDY OF RATIONS FED TO MILCH COWS. 99 



second test and the cost was reduced. This was due to the 

 fact that the milk in the second test contained a higher average 

 percentage of butter fat. 



Herd V. Tests Nos. 6j and 6^. — The total number of cows 

 in each of the tests with this herd was seventeen, twelve of 

 which were grade Jerseys, four grade Holsteins and one a 

 Devon. The cows varied in estimated weight from 750 to 

 1,000 pounds, the average being placed at 800 pounds. Nearly- 

 all the cows had calved within six months previous to the first 

 test, and none were due to calve within two months after the 

 close of the second test. The cows were fed a large amount of 

 coarse fodder, consisting of black grass hay, mixed hay and 

 corn stover, and in addition quite a large proportion of corn 

 grown on the farm. 



The first test began February 4 and lasted twelve days. 

 During this test a large amount of hay and corn stover was 

 fed, the average daily allowance per cow being 21.4 pounds. 

 The grain mixture consisted of 200 pounds of wheat feed and 

 about 150 pounds of corn and cob meal, which was fed at the 

 rate of about 12.0 pounds per cow each day. The average 

 ration fed in the first test was estimated to contain 2.19 pounds 

 of digestible protein and to have a nutritive ratio of 1:7.6. 



After an interval of sixteen days the second test was begun, 

 on March 4, and continued the usual period of time. The 

 coarse fodder used dail}' in this test consisted of a total of 17 

 pounds of oat hay, black grass hay and corn stover. The basal 

 grain mixture was made up of 500 pounds of corn and cob 

 meal, 400 pounds of wheat bran, 150 pounds of cotton seed 

 meal and 125 pounds of national gluten feed, and was fed at 

 the rate of 9.5 pounds per day. The protein mixture con- 

 sisted of equal parts of cotton seed meal, national gluten feed 

 and corn and cob meal. The basal grain mixture with the 

 coarse fodder gave a ration containing approximately 2 pounds 

 of digestible protein per day, while the protein mixture fur- 

 nished approximately .2 of a pound of digestible protein for 

 each pound of the mixture. 



The cows were divided into four groups in the second test, 

 one of which (A) containing four cows received the basal ration 

 only, another (B) containing five cows received i pound of the 



