INFLUENCE OF THE PLANE OF NUTRITION UPON MILK 75 



are not satisfactorily explained by the hypothesis that under- 

 feeding causes a transfer of tissue fat to the mammary glands. 

 Blood fat analyses made during extreme underfeeding in the 

 r;ise of two cows failed to show any increase in the amount of 

 fat carried by the blood stream in comparison with normal 

 conditions in the same animals. 



The effects of underfeeding on the composition and proper- 

 ties of milk and butter fat show the importance of controlling 

 this factor in feeding experiments involving the effects of 

 specific feeds on the composition of milk and butter. 



The effects of underfeeding must be taken into account 

 in the interpretation of all data involving variations in the 

 composition of milk and butter fat due to specific conditions 

 of the cow, specific environments of the cow, changes in the 

 feed of the cow, or to feeds of specific character. 



