316 The Feeding of Animals 



THE RELATION OF FOOD TO THE COMPOSITION AND 

 QUALITY OF MILK 



There is a widely prevailing opinion among the 

 farming public that the character of milk is inti- 

 mately related to the kind and quantity of food from 

 which it is produced, i. e., that a dairyman who is 

 possessed of sufficient knowledge may, by variations in 

 the rations, cause material changes in the composition 

 of the milk of his herd. This is equivalent to believ- 

 ing that thin milk or rich milk, milk rich in fats and 

 poor in casein or the reverse, may be obtained at the 

 will of the feeder. Such a view in its extreme form 

 is very far from the truth. While below a certain 

 limit for each cow the quantity of milk is mostly de- 

 termined by the ration, other factors, such as breed, 

 individuality and period of lactation are much more 

 potent than the food in fixing its composition. 



In discussing this topic, it must be confessed first 

 of all that the experiments touching its several phases 

 have not furnished information satisfactorily definite 

 and conclusive in all respects. The testimony arrived 

 at is more or less confusing and contradictory. There 

 are several directions in which it has been necessary to 

 look for the effect of food upon milk: (1) Effect upon 

 composition: (a) in changing the proportion of water 

 and total solid matter; (b) in changing the relative 

 proportions of proteids, fat and sugar; (c) in changing 

 the constituents of the fat. (2) Effect upon flavor. 



1. (a) Effect of food upon the composition of milk. 

 In discussing the effect of food upon the proportion 



