DAIRYING 53 



The figures show the characteristic richness* of the milk of 

 these different breeds and their milk production. The cows were 

 selected at that time for the purpose of making as good a showing 

 as possible for each breed. The feed cost per quart of milk is low- 

 est in the case of the best Holstein cow and the feed cost per pound 

 of butter fat is the least with the best Jersey cow, but there were 

 cows in each of the breeds which produced both milk and butter 

 more economically than some one cow in every other breed. 



. BB. Feed. 



209. The calculation of standard feeding rations and related 

 questions will be discussed under another head, but the effect of 

 the feed on milk secretion is a matter of importance independent of 

 compounding of rations. Economical milk production depends 

 largely on healthly and active milk glands, and since such glands, 

 like muscles, are nourished by the protein feeding stuff's, an ample 

 supply of this constituent should be available in the feed of milch 

 cows. The fat in feeding stuffs is also important, as it doubtless 

 aids in supplying the fat of milk, although the food fat is changed 

 by the digestion process and does not appear as such in the milk. 

 A sufficient amount of food fat has a favorable action on milk se- 

 cretion, but an excess not only makes a feed too expensive, but it 

 may disturb digestion and thus reduce the flow of milk. An in- 

 sufficient amount of fat as well as a scanty supply of other feed 

 fails to keep the animal up to its producing capacity, and this 

 deficiency may reduce the flow of milk. It is necessary, therefore, 

 to supply the cows with an ample quantity of feed of the right 

 kind in order to keep the milk glands in a healthy and active con- 

 dition. 



Even green feeds are not always nutritious, as it is well 

 known that pasture grass and other feeds grown during a continued 

 wet spell of weather have "no strength" as stock feed, and brew- 

 ery slop feed, roots, etc., fed in too large quantities do not aid 



* See also page 24, Lesson i. 



