ECONOMICAL USE OF FOOD 67 



Feeding for Milk Production. — Feeding for the pro- 

 duction of milk differs from feeding for the production of 

 body fat. The ration for fat production needs to supply 

 only sufficient protein and mineral matter to repair waste 

 and build up a small amount of new tissue. The bulk of 

 the body fat is built up from the carbohydrate and fat ma- 

 terial in the ration in excess of the amount necessary for 

 maintenance. On the other hand, in the production of 

 milk there is the constant need for protein and mineral 

 matter in the milk which the cow secretes. Considerable 

 protein and mineral matter are therefore necessary in 

 the ration to supply the demands of the milk-producing 

 animal. ' 



The Dairy Cow an Economical Food Producer. — The 

 dairy cow makes the most economical use of the food given 

 her. The constant outlet of milk prevents her system 

 from becoming clogged, as in the case of the steer deposit- 

 ing fat. There is perhaps more variation in the ability 

 of different cows to produce milk than in the ability of 

 steers to lay on fat. Several factors cause a variation in 

 the cost of producing milk. In the same herd one cow may 

 make a good profit, while another, under the same con- 

 ditions, may show actual loss. While a competent judge 

 may be able to determine quite accurately from external 

 appearances the fattening qualities of a steer, only an ap- 

 proximation of the ability of the cow to produce milk can 

 be so made. 



Care as Essential as Feed. — The amount and character 

 of feed given is a large factor in milk production. Cows 

 that are expected to produce heavily must be liberally fed. 

 The ration of the cow should be palatable and contain a 

 liberal supply of protein and mineral niatter. 



