Milk and Its Products. 



275 



cleanse the alimentary tract and properly start the work of di- 

 gestion. After eight or ten days from calving the secretion be- 

 comes like normal milk, but the colostrum cells can usually be 

 found in the milk for about 14 days after calving. 



The milk during the first month after calving is generally rich 

 in fat and total solids, and these diminish during the second 

 month. After the second or third month, the fat and protein, 

 as well as the sugar, continue to increase from month to month 

 during the entire period of lactation. The following table, taken 

 from the data of the New York State Station, represents the 

 monthly averages of nearly 100 different lactation periods. 



Influence of Lactation on th? Composition of Milk. 



Occasionally individuals may depart from the general ten- 

 dency shown in the above table, but usually they conform to the 

 general rule which the table indicates. The average size of the 

 fat globules diminishes with advancing lactation, but their num- 

 ber per unit volume increases. 



Feed. The influence of the feed of cows upon the composition 

 of their milk is a matter upon which many varied opinions are 

 held. There is a widespread belief that this influence is con- 

 siderable, but all experimental evidence shows it to be very small. 

 Under scanty food supply the quality and especially the quantity 



