DAIRY MEETING. 177 



away with any chance of thus transmitting trouble from one 

 farm to another, and thus result in avoiding financial loss to any 

 milk producer except the one on whose farm the trouble actual- 

 ly occurs. 



From the above it is seen that the stable offers chances of 

 pollution of milk by both solid and bacterial dirt, while the milk 

 room offers the greater chance for bacterial pollution alone. 

 Now let us see what bacteria are introduced into the milk at 

 these various places. 



First, let us consider the milk as it comes from the cow. A 

 healthy cow secretes milk that is sterile, or practically so. Bac- 

 terial contamination enters the milk after it leaves the cow, or 

 in the process of leaving her. The healthy cow does not secrete 

 a germ laden milk under any conditions, so she is never the 

 guilty party. Still, milk does not come from the cow entirely 

 free of bacteria. It is an impossibility to keep the teats of a 

 cow sterile, and is a waste of time to try to do so, but it is no 

 waste of time to try to keep the teats clean, and so keep down 

 the number of bacteria that may come from them. Granting, 

 then, the necessary presence of bacteria on the teats, and re- 

 membering that the openings of the teats are of great size com- 

 pared with the bacteria and that the milk at the body tempera- 

 ture of the cow is a fine media for bacteria to grow in, we can 

 readily see that the milk in the lower ducts will be of consider- 

 able bacterial content. Naturally then the first jets drawn will 

 contain many bacteria, as these jets will wash out the ducts; and 

 so the common practice of wasting the first few jets of milk has 

 a solid bacterial basis. Each succeeding stream will wash the 

 ducts more thoroughly, so that the strippings will be practically 

 sterile as they come from a healthy cow. Under these condi- 

 tions the bacteria which enter the milk in this way are of little 

 consequence, provided their subsequent growth can be con- 

 trolled so as to prevent such multiplication as will produce sour- 

 ing of the milk. 



On the other hand, if the cow has any local disease of the ud- 

 der the milk will come from her contaminated with the bacteria 

 which cause this disease. That such germs can live to pass into 

 the body of the user of the milk and there cause the same dis- 

 ease has had many a proof. Thus tuberculosis of the udder can 

 cause the same disease both in human beings drinking the milk, 



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