444 Feeds and Feeding. 



by the majority of persons using milk. Rye, when pastured, 

 gives an unpleasant flavor to milk, not detected by all, but by 

 many. Grass has a marked effect on the flavor of butter, de- 

 tected by all in spring when the cows are first changed from diy 

 feed to pasture. This flavor is soon unnoticed, but whether it 

 really disappears, or is unobserved because of familiarity brought 

 about by daily use, is an open question. The intensity of flavors 

 and odors in milk originating from certain feeds probably varies 

 with different cows, the milk of some showing these faults in a 

 more marked degree than others. Often odors and flavors in 

 milk charged to the cow are due to contamination of the milk 

 after it is drawTi and while left in the stable or elsewhere. 



679. A review of the subject. — Eeviewing the matter, it seems 

 from the data at hand that it is possible to vary the composition 

 of cow's milk for short periods by marked changes in the character 

 of the feed supplied, there being an increase of one or two-tenths 

 of one per cent, of fat when feeds rich in protein are given, 

 though sometimes the change is the other way. The extensive 

 Danish investigations conclusively show that the dairy farmer 

 cannot hope to measurably increase the percentage of fat in hia 

 milk by any practicable system of feeding. 



It is remarkable that dairymen have so generally held p^n er- 

 roneous opinion regarding the ability of feed to permanently af- 

 fect the quality of milk. They have doubtless been led into this 

 error because with any marked improvement of the ration for the 

 cow there has always come a larger flow of milk, and consequently 

 a larger total amount of fat. It would appear that the variations 

 in the fat percentage of milk are oftener brought about by nervous 

 influences than through the character of the feed supplied. Even 

 the variations found when first changing to new rations may be a 

 nervous rather than a feed effect, thus explaining why the change 

 is but temporary. 



When the function of milk is considered, the view here held as 

 to its stability of composition seems rational. K the milk of the 

 dam were subject to marked or violent fluctuations, varying in 

 composition with every smaU change in quantity or quality of 

 food-supply, the welfare of the young animal receiving it would 



