316 THE CHEMISTRY OF DAIRYING 



Chemical analysis shows that colostrum always contains 

 less water, i.e. more solids than ordinary milk. The average 

 composition is as follows : 



Per cent. 



Water 71-69 



Fat 3-37 



Casein 4/83 



Albumin and Globulin J 5'85 



Sugar 2*48 



Ash 178 



lOO'OO 



It will be seen that the total solids amount to 28*3 per 

 cent. The percentage of fat is about the same as in ordinary 

 milk, but it differs in character. It has a higher melting-point, 

 and exhibits a peculiar smell and taste. When colostrum is 

 allowed to stand, a cream-like layer, which may amount to 

 about half the total volume, rises to the top. This, however, 

 is not ordinary cream. It contains a much smaller percentage 

 of fat, and is quite useless for butter making. 



The percentage of casein is somewhat higher than in 

 ordinary milk ; but the difference is trifling as compared with 

 that of the lacto-globulin and albumin. In ordinary milk 

 these two, together, may amount to about 0*5 per cent., whereas 

 in colostrum they amount to over 15 per cent., i.e. more than 

 thirty times as much. It is to the presence of this albumin 

 that colostrum chiefly owes its peculiar properties. It is 

 viscous (slimy) in character, and is the chief constituent of the 

 enormous amount of so-called cream which separates on 

 standing. It readily coagulates on warming, forming a bulky 

 solid mass. 



The percentage of sugar is only about half that found in 

 ordinary milk, and the sugar is not lactose but dextrose. All 

 the other constituents are present in larger quantity. Even 

 the percentage of ash is more than doubled, and about one- 

 half of it consists of phosphoric acid. This constituent forms 

 less than a third of the total ash in ordinary milk. 



Milk of other Animals. The term "milk," when used 

 without qualification, almost invariably refers to cow's milk, 

 which is by far the most important ; and it is in that sense 



