566 ANNUAL REPORT OF THE Off. Doc. 



handled under ordinary conditions, is found to cocktain large num 

 bers, often several hundred thousand in one cubic centimeter (some- 

 what less than owe-quartei- of an ordinary teaspoonful). The more 

 dirt there is in milk, the more bacteria there will be. Bacteria and 

 dirt always go together in dairy matters. The bacteria found in 

 milk come from the following sources: 



(1) Dairy Utensils. Primarily the milk-pails, strainers and milk- 

 cans. The cracks and joints of all utensils made of tin, unless great 

 care in cleaning is used, contain dirt that holds large numbers 

 of bacteria. Rust and imperfect soldering of joints furnish places 

 for dirt to get out of easy reach. Without prompt and extreme care, 

 strainers easily become filthy and are then simply breeding places 

 for bacteria. When milk cans are used for carrying back to the 

 farm from the cheese factory or creamery whey or skim-milk, the 

 cans often are not cleaned promptly, and, when finally attended to, 

 are not treated with proper thoroughness. Through the medium of 

 a dirty skim-milk tank or whey-vat, filth germs of one form may 

 be distributed throughout the whole neighborhood. Even epidemics 

 of typhoid fever have been traced to this source of infection. 



(2.) Udder Cavity. — The milk first drawn usually contains more 

 bacteria than that drawn later. The end of the teat furnishes a 

 good place for bacteria to grow, and some are able, sooner or later, 

 to penetrate upward through the milk duct into the milk cistern 

 and grow there to some extent. The first streams of milk drawn 

 serve to wash out the lower portion of the milk cistern and the 

 duct, and thus carry down bacteria in larger numbers than appear 

 ^ater. 



(3.) Bodies of Cows. — The hair on cows favors the accumulation 

 of dirt and dust. The condition is worse in proportion as cows are 

 not regularly and thoroughly cleaned. Dust particles and hairs, 

 'aden wath bacteria, are in position to drop into the milk pail. While 

 the hairs and coarse chunks of dirt may be removed from milk by 

 straining, the bacteria are, in large part, washed off into the milk and 

 cannot be removed by any ordinary process of straining. 



(4.) Milkers. — The hands and clothing of a milker may easily be 

 loaded with bacteria and thus become a source of infection. Par- 

 ticularly objectionable is the filthy practice of some milkers of moist- 

 ening the hands with milk. 



(5.) Air of Stable. — A dirty condition of the floors, walls and ceil- 

 ings of a stable all tend to contaminate milk. Any condition in 

 the stable that affords a supply of floating dust at the time of milk- 

 ing furnishes additional bacteria for milk. 



