266 DAIRY CATTLE AND MILK PRODUCTION 



centrated that it does not have sufficient bulk. The cow 

 should be fed practically all the roughness she will eat up 

 clean, at all times, and the difference in rations fed to cows pro- 

 ducing different quantities of milk should be in the grain ration. 



A cow on a good ration of roughness will maintain herself 

 and produce a certain amount of milk. If she be a cow of 

 much dairy capacity, she will not produce milk to anything 

 like her maximum without having a portion of her ration in 

 the form of concentrates. The point is, the milk-producing 

 function has been developed to such an extent that it is im- 

 possible for the digestive apparatus of the cow, efficient as 

 it is, to extract sufficient nutrients from coarse feeds to supply 

 the enormous drain upon the body resulting from the secre- 

 tion of large quantities of milk. 



The mistake is at times made of assuming that cows all 

 receive the same ration when a uniform grain ration is fed. 

 The difference in the amount of roughness consumed is 

 generally overlooked in these cases, since the animals can 

 eat at will. If a grain ration be increased which is already 

 ample the animal consumes less roughness and may not con- 

 sume any more nutrients than before, although usually such 

 is the case on account of the greater palatability of the con- 

 centrates. In herds where all cows receive the same grain 

 ration, close observation will show that the light milkers are 

 consuming less forage than the heavier milk producers. Since 

 roughness is usually a cheaper source of nutrients than grains, 

 it is desirable to have a liberal amount of this class consumed. 

 The amount can be regulated by giving the animal all she 

 will consume of the roughness, and in addition concentrates 

 to supply the nutrients necessary for the amount of milk 

 she is producing. 



