8 



BULLETIX 1097, IJ. S. DEPARTMEXT OF AGRICULTURE. 



when from 30 to 50 pounds of silage were fed daily to cows in two 

 feedings, one hour before each milking, in an unventilated barn, a 

 feed flavor and odor were imparted to the milk of the cows re- 

 ceiving silage. 



The flavors and odors in the milk and cream from the alternate 

 cows not receiving silage were usually described as " good," " excel- 

 lent," "mild," "natural," and "normaL" The milk from the cows 

 not fed silage furnished a check on the effects of the odors present in 

 the barn air. Table 2 shows conclusively that when cows were kept 

 in an unventilated barn in which the corn-silage odor was present to 

 a greater degree than under reasonably good farm feeding conditions 

 the examiners, looking painstakingly for such, did not find a feed 

 flavor and odor except in a comparatively few cases. These were 

 silage taints probably due to carrying over such taint within the body 

 from previous feeding, as demonstrated in subsequent experiments. 

 These results show that the more or less common opinion that silage 

 flavors are air-borne to milk is not true to the degree coinmonly sup- 

 posed. They also show that milk from cows fed silage under the 

 conditions of this experiment does take on, through the body, the 

 silage flavor and odor. 



3. FEEDING 10 POUNDS OF CORN SILAGE BEFORE MILKING. 



Having determined that the odor of corn silage is usually body- 

 borne to milk, the next step was to ascertain the number of pounds 

 of corn silage which could be fed to cows one hour previous to milk- 

 ing before such milk would take on sufficient silage flavor and odor 

 through the body to be recognized by those looking carefully for 

 the same. Table 3 shows the result from samples drawn from the 

 mixed milk of cows each receiving 10 pounds of silage. The barn 

 was well ventilated in this and all experiments which follow. 



Table 3. — Effect of feeding 10 pounds of corn silage per cotv once a day one hour 



he fore milking. 



Result of sampling. 



Milk from cows fed 

 silage. 



Millr from 

 cows not 

 fed silage. 



Before After 

 aeration, aeration. 



Nninhfir nf p.-x-aminatioTis 



51 



51 



51 







Off flavor 



44 

 7 



38 

 13 



2 



No off flavor 



49 







Ofltodor . . 



41 

 10 



35 

 16 



2 



No off odor 



49 







The flavors and odors of milk from the cows fed silage were de- 

 scribed as " slight feed," " sweetish feed," or " silage." These re- 

 sults show that the feeding of 10 pounds of corn silage to cows one 

 hour before milking gave the milk a sufficient feed flavor to be recog- 



