SOURCES OF INFECTIOH IN THE STABLE. 53 



seeded with innumerable bacteria, a similar plate placed 

 at exactly the same spot two hours after the feeding and 

 the cleaning in the stable was done, did not become greatly 

 infected with bacteria during ten minutes' exposure. This 

 shows plainly that it is possible to considerably decrease 

 the infection of the milk through the air of the stable. It 

 is only necessary for this purpose that chores which con- 

 taminate the air be done with the greatest care, and not 

 performed at the time of or shortly before milking. 



Time of Feeding. On many farms it is the custom to 

 feed the cows directly before or during milking. The 

 intention is to direct the attention of the cow away from 

 the milking, or to induce her to stand quiet during 

 the process. It is, however, apparent that it is not nat- 

 ural for a cow to eat while she is being milked, from the 

 fact that she stops eating when the calf begins sucking 

 her, and that she never grazes in the pasture while the 

 milking takes place. I do not believe that feeding imme- 

 diately before or during the milking tends to keep the cow 

 quiet. But even if the method should bring this about, it 

 is nevertheless to be rejected. Feeding directly before or 

 during the milking leads largely to a contamination of the 

 milk, especially when the cows are fed coarse fodders.* 

 Masses of dust with accompanying bacteria are set in mo- 

 tion during the feeding. Hesse states that the air in the 

 stable in his experiments contained so many bacteria and 

 especially molds when the feeding took place that it was 

 impossible to count them. In an instance where very 

 rusty chaff and straw was fed in a stable I found the air 



* Bee also Weigmann and Zirn, on the source of bacteria in milk, 

 Milch Zeitung, 22, (1893) 569; Exp. Sta. Record 5, p. 431. W. 



