54 MANUAL OF MILK PRODUCTS 



Effect of food on percentage of fat in milk. 



The question as to whether the percentage of fat can be in- 

 creased by feeding has long held the attention of dairymen. 

 Much experimental work has been done on this subject, and 

 while the results differ somewhat, in the main, they agree in 

 demonstrating that, while sudden or radical changes in feed 

 may affect the percentage of fat in the milk, it is not possible 

 materially to increase the percentage of fat at all permanently. 

 Following changes in feed, the percentage of fat soon tends to 

 return to the normal for the particular cow or herd. 



After studying the effect of food on the quality of milk, 

 Whitcher J of the New Hampshire Station states his conclusions 

 as follows : 



"I feel warranted in saying that a given animal by heredity 

 is so constituted that she will give a milk of certain average 

 composition; by judicious or injudicious feeding the amount 

 of milk daily may be very largely varied, but the quality of the 

 product will be chiefly determined by the individuality of the 

 cow. A Shorthorn cow can never, by feeding, be changed into 

 a Jersey ; and the man who starts out to increase the fat in milk 

 by simply changing the food has, in my opinion, a very difficult 

 task to perform. Slight variations are always cropping out, 

 whether we change the food or not, but changes of per cent of 

 fat, of any considerable amount, do not appear to trace to food 

 influence, so long as the food is reasonably well proportioned 

 and sufficient in quantity. 



" Quantity is the result of food influence. Quality is the result 

 of the make-up of the animal." 



The influence of feed was studied at the New York Experi- 

 ment Station by feeding cows rations poor or rich in protein 

 and in fat. The results obtained are reported 2 as follows : 



1 3d Ann. Kept. New Hampshire, p. 155. 



2 New York State Experiment Station, Bulletin No. 197. 



