ON MILK AND MILK-TESTING 9 



The water, albumin, casein, and ash all come 

 directly from the blood stream being more or less 

 changed as they pass through the very thin walls 

 of the capillaries and by the action of the glandular 

 cells. The sugar is formed from the blood. The 

 fat is derived from the breaking down of the gland 

 cells by a process of fatty degeneration and from 

 the lymph stream. The amount of milk secreted 

 depends upon the amount and composition of the 

 blood and lymph carried to and from the udder 

 in a given time and also upon the activity of cell 

 construction and cell destruction in the mammary 

 glands. 



What is colostrum? 



Colostrum, or beastings, is the first milk secreted 

 by a cow after the birth of her calf. 



What is the average composition of colostrum? 

 (Konig.) 



Water 74-6% 



Fat 3.6% 



Casein 4.0% 



Albumin 13-6% 



Sugar 2.7% 



Ash 1.5% 



The composition of colostrum varies in individ- 

 ual cows to such an extent that only an average 

 composition can be given. 



How does colostrum differ in composition from 

 ordinary milk? 

 Colostrum contains less water, less fat, less sugar, 

 more casein, more albumin, and more ash. It is higher 



