VARIATIONS OF MILK CONSTITUENTS 



173 



INFLUENCE OF BREED UPON THE RELATION OF CASEIN 



AND ALBUMIN 



Name of breed 



Per cent 



of 



proteins 



(casein 



and 



albumin) 



Per cent 

 of 

 casein 



Per cent 



of 

 albumin 



Parts of casein 

 for one part 

 of albumin 



Per cent 

 ol total 



proteins 

 inform 



of 

 casein 



Holstein-Friesian.. . . 



Ayrshire 



American Holdemess 



Shorthorn 



Devon 



Guernsey 



Jersey 



77.5 

 80.1 

 79.2 

 81.3 

 73.9 

 81.7 

 82.3 



than in case of milks higher in fat. Thus, in the 

 milk of Holstein-Friesian cows, we have the least 

 amount of fat (3.26 per cent), and the casein forms 

 a smaller part (77.5 per cent), and the albumin a 

 larger part (22.5 per cent), of the proteins than in 

 case of any other breed under discussion. In the 

 case of Guernsey and Jersey milk, in which the fat 

 content is highest, the proportion of casein to pro- 

 teins is greatest (about 82 per cent), while it is least 

 for albumin (about 18 per cent). In its practical 

 application, these results mean that, in the case of 

 Jersey and Guernsey milk, a larger proportion of the 

 proteins is utilized in cheese-making and a smaller 

 proportion is lost in whey. 



The relation of casein and albumin, as shown by 

 the following data, is remarkably uniform during 

 the first eight or nine months of lactation, varying 

 between 4.1 and 4.2 parts of casein for one of 

 albumin ; or, stated in another way, the percentage 

 of total proteins in the form of casein varied from 

 80.3 to 80.9 and, in the form of albumin, from 19. 1 



