426 FEEDING FARM ANIMALS 



Breed influences the constituents of milk more prob- 

 ably than anything else, with the exception of species. The 

 difference in the components of the milk of mares and of 

 cows is greater than the difference in the same between 

 cows of one and the same breed. Some breeds produce 

 milk with a higher percentage of butter fat than others. 

 The difference is marked, averaging in many instances as 

 much as I per cent. Milk richest in butter fat comes 

 from the Channel island breeds. Breed also affects color in 

 milk and in some degree taste, since increase or decrease in 

 percentage of fat influences taste. Taste may vary in in- 

 dividuals, but, usually the more fat the milk contains, the 

 more agreeable is the taste considered. The bright straw 

 colored tint in milk increases with the percentage of fat 

 and vice versa. The influence on color extends also to 

 butter made from the milk. The Guernsey breed is pro- 

 verbial for producing butter that is rich in color, that is 

 butter of a bright yellowish hue. The influence of grade 

 on milk in the cows is the same in kind as that of breed 

 but less in degree. This means for instance that the higher 

 the percentage of Jersey blood in Jersey grades the higher 

 relatively will be the percentage of fat in the milk. But 

 not until quite a number of generations of Jersey grades 

 have been produced will the per cent of fat in the milk 

 test as high on the average as the milk of the pure Jersey, 

 (seep. 41). 



The difference in the quality of milk, more especially 

 with reference to the amount of butter fat which it contains 

 is sometimes greater within the breed or grade than it is 

 between breeds. In extreme instances it may average as 

 much as 2 per cent. The immediate cause is the char- 

 acter of the milk gland. One cow of the same age and 

 breed, fed on precisely the same kind of food, and under 

 exactly the same conditions, will furnish much less milk 

 and milk also less rich in butter fat than another cow and 

 no amount of forcing can make the former produce equal 

 to the latter since the milk gland has not the same capacity 



