EFFECT OF SILAGE ON FLAVOR AND ODOR OF MILK. 3 



most city regulations. The object was not only to get a milking cham- 

 ber which would hold odors, but, by cutting down the space one-half, 

 to intensify still further the degree of feed odors in the stable air. 

 This condition was necessary during the absorption work of the in- 

 vestigation. The silo was at a considerable distance from this barn. 



Four cows, each giving about 10 pounds of milk daily, of approx- 

 imately 4 per cent butterfat, were selected from the Dairy Division 

 herd. Only those animals which gave milk free from decided off 

 flavors and off odors were selected and these were transferred to 

 the small barn. The milk in all cases was drawn by milkers who 

 gave close attention to the cleanliness of the cows and stable and of 

 their own hands. The cows were alternated from time to time in 

 order to equalize any abnormal results due to the milk of any indi- 

 vidual animal. For example, in working with the first absorption 

 phase, each pair of cows was milked outside the barn on alternate 

 afternoons. At intervals, the individuals in each pair were inter- 

 changed. 



During these experiments the cows when producing the check 

 samples were fed on a basic grain and hay ration which did not ap- 

 preciably affect the flavor and odor of the milk they produced. 



In all the work, the milk from the different pairs was drawn into 

 sterilized, covered pails, and the milk from each pair strained through 

 filter cloth into a separate can that had been sterilized. The utensils 

 were steamed in a sterilizer for 30 minutes, and afterwards allowed 

 to remain there until used, 



METHOD OF SAMPLING. 



After milking, the two cans of milk were promptly carried from 

 the barn to the milk room, the milk in each can stirred, and samj^les 

 taken. The milk from each pair of cows was emptied into a gravity 

 creaming can and with the samples was placed in a refrigerator which 

 cooled and held it below 50° F. The next morning the skim milk 

 in the different cans was drawn off and samples of the cream taken. 



When the effect of aeration was studied, half of the warm milk 

 from each pair of cows was aerated by passing it over a clean surface 

 cooler, the milk resampled, the remainder placed in the refrigerator, 

 the milk allowed to cream, the skim milk drawn off, and the cream 

 also sampled. 



When, in addition, it was desired to get a standard sample known 

 to contain the flavor and odor of silage, part of the milk from the 

 cows not fed silage and not exposed to the silage odor in the milking 

 barn, while still warm, was redrawn through an apparatus contain- 

 ing the silage odor. This apparatus is shown in Figure 1. Ten 

 pounds of silage, fresh from the silo, were placed in this closed cham- 

 ber an hour before the redrawing took place. 



