GENERAL CHEMISTRY OF MILK 



109 



RATIO BETWEEN FAT AND CASEIN 



Breed. Authority. Fat 



Guernsey Hart 1 90 



Shorthorn Eckles and Shaw 1 .36 



fHart 1.72 



1 Eokles and Shaw 1 . 69 



(Hart 1.44 



I Eckles and Shaw 1.36 



[Hart 1.49 



I Eckles and Shaw 1.31 



Ayrshire . 

 Holstein . 



Casein. 



The figures show that breeds with high fat content usually 

 have a wide ratio of fat to casein. 



Van Slyke and Publow state that in milk with a high percent- 

 age of fat the albumin forms a smaller part of the total protein than 

 in milk with low fat content, when the composition of different 

 breeds is considered. Casein, on the other hand, forms a larger 

 part of the total protein when the fat content is high. These 

 statements are substantiated by Van Slyke and Publow by the 

 following figures: 



INFLUENCE OF BEEED UPON RELATION OF CASEIN AND ALBUMIN 



Breed. 



Holstein-Friesian 



Ayrshire 



Ainerican Holderness . 



Shorthorn 



Devon 



Guernsey 



Jersey 



Per cent, 

 fat. 

 3.26 

 3.76 

 4.01 

 4.28 

 4.89 

 5.38 

 5.78 



Per cent, 

 protein. 



2.84 



3.07 



3.32 



3.43 



3.93 



3.66 



3 68 



Per cent, 

 casein. 

 2.20 

 2.46 

 2.63 

 2.79 

 3.10 

 2.91 

 3 03 



Per cent, 

 albumin. 



0.64 



0.61 



0.69 



0.64 



0.83 



0.65 



65 



Relation 

 of casein 

 to al- 

 bumin. 



3.4 

 4.0 



3 8 

 4.5 

 3.7 

 4.5 



4 7 



Per cent. 



casein 



of 

 protem. 

 . 77.5 



80.1 



79.2 



81.3 



78.9 



81.7 



82.3 



Jersey milk with a high percentage of fat has 82.3 per cent, of 

 the total protein as casein and 17.7 per cent, albumin, while 

 Holstein milk has only 77.5 per cent, of the total protein as casein 

 and 22.5 per cent, albumin. This information is important to 

 the cheese maker, who can obtain a higher yield of cheese from 

 milk rich in casein. 



White and Judkins show the variation in composition of milk 

 from different breeds in the following figures: 



VARIATION IN COMPOSITION OF MILK FROM DIFFERENT BREEDS 



Breed. 



Average. 



Limits. 



Plasma solids. 



Average. 



Limits. 



Jerseys. . . 

 Guernseys 

 Ayrshires . 

 Holsteins . 



5.32 

 4.49 

 4.10 

 3.41 



4.25 to 6.49 

 4.12 to4.79 

 3.85 to 4.42 

 3.02 to 3.86 



9.07 



8 52 to 9.56 

 8.57 to 9.27 

 8.62 to 9.24 

 8.09 to 8.83 



Milk-sugar and ash: There is no appreciable variation in the 

 percentage of sugar and ash in the milk of different breeds. 



