8 THE CONTAMINATION OF MILK. 



(with strainer) will exclude as high as 97% of the bacteria 

 that fall into the common open pail (59). A strainer of 

 absorbent cotton apparently enmeshes some bacteria and keeps 

 them from the milk. Tests of the Gurler pail have shown 

 that the use of cotton reduces the bacterial count to 30% of 

 that obtained when the pail is used without the strainer (61). 



The milker. The milker is the most important factor in 

 the production of clean milk. Success or failure depends 

 upon his training and faithfulness in carrying out details, the 

 significance of which he may not appreciate nor respect. 

 Milkers, with the exception of a very few in model dairies, 

 trained by bacteriologists, exhibit a low degree of cleanliness 

 in their work. The results obtained by different men, working 

 under the same rules for asepsis, are striking. A group of 

 five students in the Connecticut Agricultural College, trained 

 in the theory of dairy bacteriology, were able to draw milk 

 with one-third the bacterial content of that drawn by the two 

 regular milkers. A well trained college graduate, in charge 

 of the dairy herd, was able to obtain results seven times as 

 good as those obtained by the same two milkers (60). The 

 practice of wetting the hands with milk, which afterwards 

 drips from the teat into the pail, is far from uncommon. It is 

 usually not the practice even to wash the hands before milking. 

 The practice of providing clean overalls for the milkers should 

 be more general. In some certified dairies the milker wears a 

 freshly sterilized suit at each milking period, washes his hands 

 after milking each cow, and uses a sterilized milking stool. 

 The milker as a factor in the contamination of milk with the 

 germs of the infectious diseases of man, will receive consider- 

 ation in Chap. III. 



Milking machines. The advent of the milking machine has 

 been welcomed by some, with the idea that its use would 

 practically eliminate the sources of bacterial contamination 

 within the stable. Hopes in this direction have not been 

 entirely realized. The machine necessitates bringing milk into 

 contact with rubber tubes, which have long been recognized 

 as objectionable. Rubber is very difficult to cleanse thoroughly, 

 in a bacteriological sense, and it is certain that the care given 



