128 DAIRY FARMING 



in some cows to produce a soft butter fat, in others to 

 produce a hard butter fat, even in cows of the same breed. 



Soluble Fats. The soluble or volatile fats, of which 

 butyrin is the most important, give milk and sweet cream 

 butter their characteristic flavors. Butyrin is found only 

 in butter fat and distinguishes this from all vegetable 

 and other animal fats. 



The percentage of soluble fats decreases with the period 

 of lactation, also with the feeding of dry feeds and those 

 rich in protein. Succulent feeds and those rich in carbo- 

 hydrates, according to experiments made in Holland and 

 elsewhere, increase the percentage of soluble fats. This 

 may partly account for the superiority of the flavor of 

 June butter. 



It may be proper, also, to discuss under volatile or 

 soluble fats those abnormal flavors that are imparted to 

 milk, cream, and butter by weeds like garlic and wild 

 onions, and by various feeds such as beet tops, rape, par- 

 tially spoiled silage, etc. These flavors are undoubtedly 

 due to abnormal volatile fats. 



Cows should never be fed strong flavored feeds shortly 

 before milking. When this is done the odors are sure 

 to be transmitted to the milk and the products therefrom. 

 When, however, feeds of this kind are fed shortly after 

 milking no bad effects will be noticed at the next milking. 



Albumenoids. These are nitrogenous compounds 

 which give milk its high dietetic value. Casein, albumen, 

 globulin, and nuclein form the albumenoids of milk, the 

 casein and albumen being by far the most important. 



Casein. This is a white colloidal substance, possessing 

 neither taste nor smell. It is the most important tissue- 

 forming constituent of milk and forms the basis of an 

 almost endless variety of cheese. 



