358 MISSOURI AGRICULTURAL EXP. STA., RESEARCH BULLETIN NO. IO 



The Pigments of the Fat from Colostrum Milk. It is a well known 

 fact that the first milk drawn after parturition always has a high 

 yellow color. It is not generally known, however, that this high 

 color is usually due 1 entirely to the suspended fat globules. We have 

 many times observed, not only in connection with this study but 

 also in connection with numerous studies dealing with the chemical 

 composition of milk, that when the fat is entirely removed from 

 colostrum milk the skim milk has the appearance of ordinary skim 

 milk, and the butter and the rendered fat have a depth of color 

 which is never equaled at any subsequent stage of the lactation period. 

 This characteristic of colostrum milk is common to all breeds of cows, 

 and the high color of the fat continues in cows of all breeds for a 

 short time after parturition and then gradually falls off. Table 8 gives 

 the color of the milk fat of several cows shortly after parturition and 

 again a week or two later. The color readings are the Lovibond tin- 

 tometer readings of a one-inch layer of melted, rendered fat. 

 TABLE No. 8. COLOR OF THE FAT OF COLOSTRUM MILK. 



(a) The Alfalfa hay was rich in carotin and xanthophylls. 



(b) Second sample taken after next parturition. 



This phenomenon at once offered the interesting problem of 



the relation of the colostrum pigment to the pigment of normal 



butter. A close study was accordingly made of the pigment of the 



fat from the first milk drawn after parturition. The cow selected 



1. Colostrum milk is occasionally contaminated with blood. 



