No. 6. DEPARTMENT OF AGRICULTURE. 223 



from here that we have had not only a profitable week but a week of 

 pleasure and you will not be afraid or ashamed to ask us back some- 

 time in the future. 



THE PKODUCTION OF SANITAEY MILK- 



By D. H. BERGEY, M. D. , University of Pennsylvania. 



By sanitary milk we understand a milk that is free from extraneous 

 things of whatever kind that may affect the health of those using it. 

 The production of sanitary milk is not a difficult matter at all, al- 

 though it requires constant vigilance on the part of the producer and 

 attention to a great many details. Bacteria are found in the milk 

 ducts of most cows and, subsequently,, it is impossible to obtain con- 

 siderable quantities of milk without the admixture of bacteria. The 

 bacteria in the milk ducts of apparently healthy cows are principally 

 those who are concerned in the natural souring of milk. These bac- 

 teria are, therefore, regarded as normal constitutents of milk. 



The most common organism found in freshly drawn milk is micro- 

 coccus lacticus. In many of its characters this bacteria resembles mi- 

 crococcus aureous, which is the most frequent cause of pus formation 

 in man and domestic animals. Another organism found in freshly 

 drawn milk is streptococcus lacticus. This bacterium is not easily 

 distinguishable from streptococcus pyogenes, another of the bacteria 

 causing i)us formation. These two organisms found in the milk sinews 

 of apparently healthy cows appear, from the effects which they pro- 

 duce in milk, to be normal inhabitants of this portion of the cow's 

 udder and, therefore, have no hygienic significance. 



IMilk may be said to be contaminated with bacteria when it contains 

 organisms which differ from those mentioned. The contaminating 

 bacteria may be derived from a variety of sources. The principal 

 sources of contamination of milk in the course of production and 

 marketing are to be sought in the dairy itself. The chief sources of 

 contamination are the cow from which the milk is obtained; the 

 stable; the bedding; the fodder; the milker or the utensils in which 

 the milk is collected. 



The cow may be the source from which contaminating organisms 

 are derived and these organisms may gain access to the milk because 

 the animal is ill and the bacteria causing the disease are given off with 

 the milk ; or second, the contamination may be derived from the fur of 

 the cow or from a dirty udder. 



Cows do not suffer from many diseases to which human beings are 

 also liable. The principal diseases that may be disseminated from the 

 cow to the consumer through the milk are the various types of inflam- 

 mation of the udder giving rise to disturbances of the digestive organs 

 in those using the milk; tuberculosis; foot and mouth diease; apd 



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