FARM ANIMALS 177 



It is interesting to note the sources of the fat in 

 milk, and numerous experiments have been with 

 this definite idea in view. From these experiments, 

 it appears that a part of the milk fat comes from the 

 sugars and starches in the food. The cow has the 

 power of manufacturing milk fat not only from 

 the fat of the food, but from the carbo-hydrates. 

 In one experiment, in which, for a period of two 

 months, the cow was fed a ration as free from fat 

 as it was possible to obtain it, the cow produced 

 eighteen and one-half pounds of milk fat, which 

 was not present in the food in any other lorm than 

 starch or sugar. During this time the cow gained 

 in weight so that the fat could not have been ob- 

 tained from the body fat of the animal. Evidently, 

 therefore, the cow is able to transform the starch 

 and sugar in her food into milk fat. 



At Cornell University an interesting and care- 

 fully planned experiment was carried out to test 

 the general problem regarding the possibility of 

 improving the quality of the milk through the 

 ration. The experiment was continued for two 

 years. It appeared as a result of this work that 

 the quality of the milk can be influenced to an 

 appreciable extent by giving attention to the com- 

 position of the ration. Thus, in the case in ques- 

 tion, an abundant ration of easily digestible and 

 nitrogenous foods resulted in an increase of one- 

 fourth of one per cent, in the milk fat. At the 

 same time the quantity of the milk was increased 

 about fifty per cent., so that the very slight increase 

 in the fat content becomes of considerable impor- 

 tance in view of the largely increased amount of 

 milk from which the fat could be removed. The 

 rations used in this experiment contained such 

 foods as are readily accessible to all farmers, and 



