DAIRY FARMING DAIRYING. 677 



advantage in favor of the open stable as a place to produce milk of a low germ 

 content. The germ content of the air in the milking room of the open stable 

 was less than in the closed stable, and fecal contamination of milk, as indi- 

 cated by a fermentation of 25 per cent or more in a lactose-bile medium, was 

 no greater than in the closed stable, where the cows require more careful 

 attention. The individuality of the animal appeared to be an important con- 

 sideration in producing milk of low bacterial content. 



The sanitary sig-nificance of body cells in milk, K. S. Brekd {Jour. Infect. 

 Diseases, I4 [1914), ^o. 1, pp. 93-99). — The conclusions drawn from the studies 

 made of the cellular content of milk are summarized by the auth<ir as follows: 



"(1) Normal milk contains cells derived from the body of the cow which are 

 of 2 entirely different types: (a) White blood corpuscles which are largely of 

 the polynuclear and polymorphonuclear type; these cells make their way into the 

 milk by passage through the epithelial lining of the secreting portion of the 

 gland, possibly, also, through the epithelial lining of the ducts of the gland; 

 (b) epithelial cells, nuclei, and cell debris discharged from the epithelial lining 

 of the secreting portion of the gland and possibly also from the ducts, 



"(2) The number of these cells in apparently normal milk is exceedingly vari- 

 able even in the milk from the same cow. The variation in the number of cells 

 in the milk from the different quadrants of the udder is almost as great as the 

 variation in number of cells in the milk of different animals. Apparently the 

 strippings always contain a greater number of cells than the milk from the 

 earlier part of the milking. 



"(3) It is very common to find milk that contains so few cells that they can 

 scarcely be counted with the method of examination used, i. e., less than 5,000 

 per cubic centimeter, but milk containing one or more millions of these cells per 

 cubic centimeter is met with frequently. The highest cell count which has been 

 found in this work was in the case of the strippings from one-quarter of the 

 udder of a cow 8 days after calving where the milk showed the enormous count 

 of 54,300,000 cells per cubic centimeter. Nevertheless, this milk was of an 

 entirely normal appearance and careful bacteriological examination of the udder 

 showed no evidence of streptococcic infection. This milk had an entirely normal 

 taste and caused no evil after-effects. 



"(4) Out of 122 individual cows whose milk has been examined, 59 have been 

 found to give cell counts under 500,000 per cubic centimeter, 36 gave counts 

 between 500,000 and 1,000,000 per cubic centimeter, and 27 gave cell counts over 

 1,000,000 per cubic centimeter. The milk of all of these cows was normal In 

 appearance and was sold or used by their owners, who had every reason to 

 suppose that the milk was normal milk. 



"(5) There are no satisfactory data at hand to show whether there is, or is 

 not, a relation between high cell counts and any of the following : Streptococcic 

 infection of the udder or other pathological conditions of the udder, colostrnl 

 milk, milk from cows that are nearly dry, in heat, or in poor condition of flesh, 

 etc. Such evidence as we have indicates that it is not at all likely that any 

 of these conditions may be recognized by cell counts alone, especially in sam- 

 ples of market milk which consist of a mixture of the milk from several 

 cows." 



The author believes that while " it is entirely possible that some of the strik- 

 ing variations in numbers have a sanitary significance, as pathological conditions 

 would certainly affect the discharge of these body cells ... [it is] impossible 

 to make even a guess as to the final conclusions regarding the significance of 

 the variations in number and character of the cells." 



Creamery bacteriology, O. Jensen (Die Bakteriologie in der Milchwirtschaft. 

 Jena, 1918, pp. 182, figs. 60).— Part 1 of this book treats of the micro-organisms 



