COLOSTRUM. 35 



properties, and assumes gradually generally after the lapse of three 

 days from calving the properties of ordinary milk. During the 

 first hours after calving it is always very rich in solids, and contains 

 large quantities of nitrogenous bodies, of which only about a half 

 are in a state of suspension. It contains only minute traces of milk- 

 sugar, sometimes none at all, but in its place small quantities of 

 other kinds of sugar. It has about the same quantity of, or even 

 less fat, than ordinary milk, and rather more mineral matter. It 

 possesses a yellowish or brownish colour, a peculiar smell, and a 

 slightly salt taste. Its reaction is generally slightly acid, and it 

 possesses a slimy, viscous appearance. It exhibits a variable re- 

 action towards rennet, and on being heated it coagulates. If kept 

 undisturbed, it often separates into two more or less distinct layers. 

 Its specific gravity at 15 C. varies between 1*046 and 1*079. 

 It is the most convenient and only natural kind of nourishment for 

 the young, and newly-born calves should on no account be deprived 

 of it, as it exercises an especial action on the intestinal canals, and 

 possesses also a high nutritive value. It is not suited for use in the 

 dairy. On this account the milk of cows, when they first begin to 

 give milk, is kept separate for four days if the milk be intended 

 for use in churning, or for ten or twelve days if it be intended to 

 use it for cream cheese. 



The composition of colostrum changes quickly, hour after hour, from 

 the period of birth, until it assumes the properties and composition of 

 ordinary milk. Of ah average composition, therefore, it is not possible to 

 speak. The following figures, however, may serve to give an indication 

 of its nature : 



Water, ... ... ... ... 78*7 per cent. 



Fat, 4 



Nitrogenous (caseous) matter, 



in suspension, 7*3 



Nitrogenous matter in solution, ... 7'5 



Sugar, ... ... ... ... 1'5 



Mineral matter, ... ... ... I'O 



Total solid matter, 

 21 "3 per cent. 



100-00 



Especially characteristic of colostrum are certain grape-shaped bodies, 

 the corps granuleux, discovered in 1836 by Donne, the diameter of which 

 lies between -005 and -025 mm. Henle has named these microscopic bodies, 

 which do not entirely disappear from cows' milk till three weeks after 



