COLOSTRUM 



241 



3. Colostrum. This is the term applied to the secre- 

 tion which is produced in the alveoli of the udder just 

 before and for a few days after parturition of the animal. 

 It is a yellow opaque liquid, alkaline in reaction, and 

 sometimes contains traces of blood. On heating it 

 becomes coagulated. A microscopic examination reveals 

 the presence in it of a number of colostrum corpuscles 

 from .005 to .025 mm. in di- 

 ameter, some of which closely 

 resemble leucocytes or white 

 blood corpuscles with irregular 

 nuclei, at the same time ex- 

 hibiting living amceboid move- 

 ment. Many of them contain 

 fat globules while others appear 

 to be more or less disintegrated 

 cells, free from fat and nuclear 

 bodies (Fig. 40). The aver- 

 age composition is near the following 



Water . . . . . 7 1 .7 per cent. 



Fat . . . . 3.4 per cent. 



Caseinogen and other proteins 20.7 per cent. 



Sugar . . . 2.5 per cent. 



Mineral matter . . 1.8 per cent. 



On comparison with the average composition given on 

 pp. 234-5 it is seen that colostrum differs very considerably 

 from milk, in containing six or seven times as much 

 proteins, less water, less sugar, and more mineral matter. 

 The fat in it is of a more solid character than that of 

 ordinary milk and the proteins consist of a little 

 caseinogen with a larger proportion 12 to 14 per cent. 

 of albumin and globulin which are usually present in 



