MANITAL OF CATTLE-FEEDING. 425 



Milk Production with Insufficient Protein.— A fod- 

 der somewhat less rieli in protein than that ii&imllj con- 

 sidered necessary will, it is true, if agreeable to the ani- 

 mals, often produce a large flow of milk. The energy of 

 production is so great in good milk cows that it continues 

 for a time unaltered, even when the fodder does not supply 

 sufficient materials. The deficiency is then supplied from 

 the body of the animal, and the latter loses flesh and fat. 



This may be admissible to a certain extent in the early 

 part of lactation, since, as the amount of milk gradually 

 decreases, the drafts on the materials of the body cease, 

 and the latter, if the fodder be tolerably rich, ma}- regain 

 what it previously lost. At the same time the detieiency 

 must not be too great, since then, as we have just seen, a 

 rapid decrease in the flow of milk takes place, and the 

 cows are liable to com6 into a condition in which even rich 

 feeding will not produce much milk. 



'Effect of Fat. — An increase of the fat of a ration seems 

 to produce but little effect upon the milk production. The 

 only conclusion that can be drawn from the experiments as 

 yet made is that it does not increase at all the percentage 

 of fat in the milk, but may slightly increase the quantity 

 o£ the milk, probably because the fat protects some of the 

 protein of the food from oxidation, and thus, by putting 

 more material at the disposal of the milk-glands, causes an 

 increased production of all the ingredients of the milk, 

 and not simply of fat. 



For example, in experiments by Wolff,* the addition of 

 a pound of fat (at first rape-seed oil, afterward linseed oil) 

 per head to a very scanty fodder which had caused a rapid 

 decrease in the flow of milk increased the flow only for 



* Loo. cit , p. 506. 



