PHYSICAL PROPERTIES OF MILK 



79 



its color, it was necessary to compare the color of the butter-fat 

 of the different breeds under comparative feeding conditions, in 

 order to obtain a correct estimate of the breed relation. 



It would naturally be expected that the most favorable 

 condition for studying the accuracy of the views held by the 

 cattle-breeders and others that some breeds of cows, such as 

 the Jersey and Guernsey, are color producers, while other breeds, 

 such as the Holstein, are not color producers, would be a com- 

 parison of the color of the combined fat of several cows of each 

 breed. The table which follows gives such a comparison taken 

 from animals in one herd. The milk and fat production of the 

 various cows varied widely. The comparison was made during 

 the winter months, the only source of pigment being a more or 

 less variable quantity of green alfalfa hay in the ration, which 

 was, however, the same for all the animals. 



Relation of Breed to Color of Milk-fat 



Breed 



Color of Butter- 



FAT 



Yellow 



' Red 



Light 



Jersey . 



Ayrshire 



Shorthorn ....... 



Holstein 



50.0 

 38.0 

 34.0 

 31.0 



2.1 



1.7 

 0,6 



a.7 



0.2 

 0.2 

 0.2 

 0.2 



The most striking fact brought out by this table is that the 

 question of the color of the fat produced by the four breeds 

 represented is not one of presence or absence of color, but rather 

 a question of relative color. The fat from the Jersey cows was 

 unquestionably the highest colored of the four samples, but the 

 fat from the Holsteins also had a very good color, although the 

 butter would probably have been scored as "slightly low in 

 color." 



