82 STORRS AGRICULTURAL EXPERIMENT STATION. 



FEEDING ACCORDING TO YIELDS OF BUTTER FAT. 



Four herds were included in the studies here reported, two 

 tests, as usual, being made with each herd. The herds were 

 lettered and the tests numbered consecutively with those of 

 former years, namely, herd T, tests 59 and 61; herd U, tests 60 

 and 62; herd V, tests 63 and 65; and herd W, tests 64 and 66. 



In each case the feeding in the first test was conducted ac- 

 cording to the usual practices of the dairyman, the kinds and 

 amounts of coarse fodders and grain feeds used being those he 

 was using when the test began. As a common thing each 

 farmer fed all his cows a uniform ration, although in some 

 cases the amount of grain feeds used was varied slightly for 

 the different cows according to whether they were fresh or well 

 advanced in lactation. An account was kept of the kinds and 

 amounts of feeds used and of the quantity of milk produced, 

 the feeds were sampled and analyzed, and the percentage of 

 fat in the daily milk of each cow was determined; in this way 

 it was learned how much of each ingredient the cow was re- 

 ceiving per day and how much milk and butter fat she was 

 producing. 



In the second test the ration was proposed by the Station 

 and was based upon the yields of butter fat. All the cows 

 included in the test were arranged in groups according to the 

 amount of butter fat per day yielded by each during the first 

 test, and all the cows in a group were fed a uniform ration. 

 The ration consisted of two parts, a basal portion and a sup- 

 plemental portion. The basal portion consisted of coarse fod- 

 ders, usually those available from the farm, and grain feeds 

 either grown on the farm or purchased. These were used in 

 such amounts and proportions as to supply approximately the 

 same amount of protein as in the average ration used in the 

 first test. The supplemental portion consisted of concentrated 

 feeding stuffs, which generally were purchased. These were 

 mixed, according to their composition, in such proportions as 

 to furnish from .2 to .3 pound of protein for every pound of 

 the mixture — called for convenience a protein mixture. This 

 mixture was kept separate from the grain feeds used as part of 

 the basal ration, so that it could be omitted or fed in varying 

 amounts as desired. In feeding, all the cows in a test were 

 given the same basal ration and some or all of the cows 



