290 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



iiiuU'r apparently clean but unwashed udtlers, 578; and under washed 

 udder's, li)*2. As the extent of bacterial contamination is closely asso- 

 ciated with the amount of dirt getting into milk, the figures cited 

 indicate clearly the value of washing the udders of cows in prevent- 

 ing contamination of milk during milking. Fraser concludes his 

 bulletin on Preventing Contamination of Milk by the following 

 paragraph : 



Paying special attention to cleanliness in every step of the production and 

 care of uiillc will result not only in clean milk, but in a marked reduction in 

 the number of bacteria it contains, which will greatly lengthen its keeping 

 qualities. That the desired results may be obtained care must be constantly 

 exercised. It is of little consequence to practice extreme cleanliness in all of 

 the steps of milk production but one. and be filthy about that one. as this spoils 

 the whole. Even if the majority of species of bacteria which ordinarily gain 

 access to milk are not dangerous to health, no one cares to consume milk in 

 which a sediment is found at the bottom if it is allowed to stand for a short 

 time. Frequently much tilth is allowed to get into milk during milking, and 

 many milkers practice the filthy habit of keeping the teats wet with milk 

 during the milking process; yet after it is drawn the greatest care is exer- 

 cised that no dust or dirt gain access to it. As far as the final result is con- 

 cerned, all painstaking care in the subsetjuent operations is lost because of the 

 careless work at the beginning during the process of milking, for if filth once 

 gains access to milk no amount of care afterwards can remedy the difliculty. 

 It is, therefore, of the greatest importance to the advancement of better dairy- 

 ing that special enqihasis be placed upon the operation where milk is liable to 

 receive the most contamination. The work rei)orted in the preceding pages 

 shows that the greatest source of contamination in milk, as ordinarily jtroduced, 

 is the cow lierself, and this is doubly important because it is the source which 

 is given the least attention in actual practice. 



Haecker and Melick" have also reported observations on the con- 

 tamination of milk during milking. Petri dishes were exposed under 

 udders which had been (1) sponged with water, (2) sponged with 

 a 5 per cent solution of carbolic acid, (3) smeared with va.seline, and 

 (4) merely brushed with the hand. The ordinary motions of ndlk- 

 ing were gone through with, but no milk was draw^n. AVhen the plates 

 were exposed in the pastuiv the number of colonies which developed 

 from exposure imder udders treated with carbolic-acid solution was 

 65, with vaseline 02, with water 120, and untreated 310. AMien the 

 exposures were made in the stable the corresponding numbers were 

 344, 34C, 483, and 20,500. These figures show the value of sponging 

 the udder as a means of reducing bacterial contamination, and also 

 the greater danger of contamination when the milking is done in the 

 stable. 



The advantages of using a covered milk pail for excluding dirt 

 from milk have been amply demonstrated by the work of W. A. 

 Stocking, jr., at the Connecticut Storrs Station.^ Two kinds of pails 



o Nebraska Sta. Bui. 87. 



& Connecticut Storrs Sta. Kpt. 1901, p. 105. 



