Procuring Sterile Milk. 153 



thing should be avoided during milking which would cause stirring 

 up of the dust, such as removal of manure and feeding. 



As long as the milk gland is in a healthy condition the cells 

 secrete a sterile product, which becomes contaminated with 

 bacteria only in the lowest part of the teats, in their ducts, or 

 during the process of milking, etc. 



Bacteria are always present in the lowest parts of the ducts 

 of the cistern, as a result of contamination from the litter. These 

 bacteria and also those which fall into the milk during milking, 

 and the massaging of the quarter, render the procuring of sterile 

 milk practically impossible, even when the strictest care is taken 

 to prevent as far as possible the subsequent contamination of 

 the milk. 



In spite of opposing views, it may be considered proved at 

 the present time that the milk in the udder is sterile as long as 

 the animal is not affected with diseases of the udder or severe 

 general affections. Lister, Miessner, Escherich, Kitt, Tromms- 

 dorff, Eullmann, Seibold and others succeeded in procuring abso- 

 lutely sterile milk. This, of course, was only in small quanti- 

 ties, and drawn with special care, such as washing the udder, 

 disinfection, protective covers, etc. 



The first streams of milk are of course always contaminated 

 with bacteria (Schulz, Luz, d'Heil) ; the subsequent ones may be 

 sterile, but frequently they also may contain bacteria, as confirmed 

 by the works of Boekhout, Ott de Vries, Ward, Koning, and 

 Freudenreich. In practice the procuring of milk with a moderate 

 number of bacteria must be considered satisfactory. Schulz, for 

 instance, found that the first milk procured contained 55,566 up 

 to 97,240 bacteria per c. c., while during the middle of the milking 

 it contained only 2,070 to 9,985, and in the last from to 500 

 bacteria. In an interrupted milking, that is, when the milk was 

 obtained in four portions, Backhaus and Appel counted in the 

 first part 170 to 950, in the second 60 to 255, in the third 10 to 70, 

 in the fourth to 45 bacteria per c. c. 



For procuring sterile milk the following measures are recommended: 



Washing the udder with soap and water, disinfection with alcohol (Kitt, Kolle) ; 

 disinfection with mercuric chloride solution (Fauss, Klimmer) ; mercuric chloride solution 

 and rinsing with boracic water and formalin (Boekhout and de Vries) ; washing with 

 a 2% mercuryoxycyanide soap (Freudenreich), followed with rubbing with sterile cotton 

 (Ostertag) ; salicylcotton (Eichert); sterile cloths (Freudenreich); and then after 

 cleaning and thoroughly disinfecting the hands of the milker with soap, water and the 

 same disinfecting agent which has been used for disinfection of the udder, the milk may 

 be carefully drawn by the usual method, which is termed ' ' fisting. ' ' 



Backhaus after a coarse cleaning of the udder, covers it with a bag which con- 

 tains disinfecting fluids. After a short action of the disinfectant the fluid is allowed 

 to escape through a stop-cock attached at the lower part of the bag and the udder is 

 rinsed with previously boiled warm water. Other authors cover the body of the animal 

 with sheets, leaving only the udder exposed. 



Boekhout, Ott de Vries and Trommsdorff used sterile milking tubes for taking 

 samples. In this operation it is to be regretted that even in the most careful manipulation 

 with sterile milking tubes, infections of the udder sometimes result. Eullmann therefore 

 prefers direct milking. He also rubs white paraffin salve into the skin of the surround- 

 ing part of the udder. 



