290 MILK 



barnyard, therefore, should not serve as a place for accumulating 

 manure and other filth, but should always be in reasonably cleanly 

 condition. 



Stables for other farm animals should be at a distance suf- 

 ficiently great to avoid contaminations from this source, and farm 

 animals should never be permitted in the cow barn. 



Dust in stable air is derived chiefly from the cow, manure, 

 fodder, the bedding, and perhaps from flies. A further source 

 of dust is that blown through open windows, but this is probably 

 the least important contribution. 



It has already been pointed out that dust from the coat of the 

 cow is shaken off by each movement. Larger particles drop on 

 the floor, but finer particles may remain suspended in the air for 

 some time. Currying the cows should, therefore, be done at a 

 sufficient length of time before milking to permit the dust from this 

 operation to settle. When this is properly done, however, the 

 germ content of the milk is reduced, and the time consumed in 

 currying cows is not great. Trueman states that a cow qan be 

 thoroughly curried in twelve to fifteen minutes. In a series of 

 14 experiments Stocking showed that the germ content of milk 

 drawn before brushing the cows was 1207, while in milk drawn 

 from cows after brushing contained 2286 per cubic centimeter. 

 These figures show how necessary it is to allow the dust to settle 

 before milking is commenced. ' 



^ That manure, when it remains in the stable or in close environ- 

 ment long enough to dry out, is a source of dust needs hardly be 

 mentioned. Prompt removal of manure is, therefore, not only 

 a sanitary measure, but aids in reducing the dust of the stable 

 air. In the best dairies manure is removed every day and, when 

 not immediately spread on the field, is placed in a pit at least 100 

 feet from the stable. Manure is a valuable fertilizer and farm 

 economy requires that it be well cared for. 



Much has been said and written about the influence of fodder 

 on the dust content of stable air. Carrying food into the stable 

 and distributing it should, therefore, be done with care, and it is 

 of further importance not to give the cows dry fodder for at least 

 one hour before milking. Stocking obtained the following results 

 by examining milk for its germ content before and after feeding; 

 Before feeding corn stover the germ content was 1233 bacteria 

 per cubic centimeter, while after feeding it was 3656. Feeding 

 hay and grain gave 2096 germs per cubic centimeter before and 

 3506 after. These figures are the averages of five estimations; 

 they show clearly that the dust from dry fodder, when given 

 shortly before milking, adds a considerable number of bacteria to 

 the milk. 



