4G Dairy Bacteriology. 



low bacterial content is secured in the latter case by the 

 elimination rather than the destruction of bacteria is a 

 point in its favor. Unquestionably such sanitary milk is 

 less changed from the normal secretion of the cow than 

 that which has been subjected to heat sufficiently high to 

 destroy the bacteria in the same. 



It may not be practical under all conditions where milk 

 is produced to put into operation all of the precautions 

 tfcat have been previously referred to. But there can be 

 no doubt where milk is to be consumed as milk, that the 

 introduction of these or similar methods would greatly 

 improve the quality of the product. Even where milk is 

 utilized in the factory or creamery, it is quite essential 

 that it should be as nearly normal as possible, for in but- 

 ter and cheese making, the quality of the product is di- 

 rectly dependent upon the character of the raw material. 



Dairymen have learned many lessons in the severe school 

 of experience, but it is earnestly to be hoped that future 

 conditions will not be summed up in the words of the 

 eminent German dairy scientist, Prof. Fleischmann, when 

 he says that "all the results of scientific investigation 

 which have found such great practical application in the 

 treatment of disease, in disinfection, and in the preserva- 

 tion of various products, are almost entirely ignored in 

 milking." 



Effect of temperature on bacterial growth. After milk 

 is once seeded with bacterial life, no one factor exerts so 

 potent an effect as temperature upon the rate of growth. 



Although different species vary in their rate of develop- 

 ment, yet moderately warm temperatures from 75 to 90 

 F., encourage rapid growth. Unless the milk is quickly 

 deprived of its original heat, the rate of the fermentative 



