VARIATION OF FAT IN MILK 73 



According to experimental evidence, milk drawn with a 

 machine contains more bacteria than milk drawn by hand. 

 This is claimed to be due to the suction on the exterior of the 

 teat, and to the tubes through which the milk must pass after 

 it is drawn. 



Fore-milk and After-milk. The fore-milk, or the milk 

 drawn from the cow's udder first, contains much less fat than 

 does the milk drawn subsequently. The very first milk drawn 



FIG. 22. Milking goats in Norway. 



appears watery and contains as little as 0.1% of fat, while 

 the very last milk in the udder may contain as high as 12%. 



The reasons assigned for this variation are (1) the milk in 

 the canal of the teat, and lower portion of the milk-reservoir 

 is present under such conditions as to allow creaming to proceed. 

 (2) The larger fat-globules are about as large as the smaller 

 milk-dusts in the cow's udder; consequently the downward 

 passage of these fat-globules meets with some obstruction 



