^EW York Ageicultckal Experiment Station. Ibo 



been caught under most favorable conditions and placed under 

 the influence of formalin within a few minutes. 



CONNECTION BETWEEN BACTERIA IN THE UDDER AND ENZYMES IN THE 



MILK. 



Previous investigators^^ have noted that there is considerable 

 difference in the rate of change caused b}^ enzymes in different 

 samples of freshly drawn milk. These differences have been 

 attributed to variations in the enzyme-forming activity of the 

 milk glands, but we have been led to look for another explana- 

 tion of these irregularities. The production of enyzmes on the 

 part of certain classes of bacteria is well known, but the 

 bacterial formation of enzymes in the udder, able to perform 

 work in cheese ripening, is a possibility which has not been 

 seriously considered. 



The work of Ward-^ has called attention to the fact that in 

 many cases the interior of the udder is inhabited by certain 

 microorganisms which find the conditions favorable to their 

 continued uevelopment. In working -with certain Station cows 

 we have found that in some cases large numbers of germs were 

 present in the milk last drawn. This condition existed when- 

 ever examinations were made during a period of some months. 



By comparing the germ content of the whole mess of milk, 

 after rejecting the milk first drawn, with the germ content of the 

 milk last drawn, or strippings, it is often found that the number 

 present in the whole mess exceeds that in the strippings by an 

 amount hardly larger than would be expected as a result of 

 unavoidable contamination during milking. 



This is shown in the following table which gives the number 

 of bacteria found per cubic centimeter in the whole mess and in 

 the strippings from each (]uarter of a single cow at three 

 successive milkings. In all cases the first few streams from 

 each quarter were rejected. 



"Babcock and Russell. See No. 10. 



'"Ward. Bui. No. 178 Cornell Exp. Sta. (1900). 



