12 



BULLETIN 642, U. S. DEPARTMENT OP AGRICULTURE. 



a week. It will be noticed that the walls and ceiling were extremely 

 dirty. Hay protruded through the open ceiling, and the gutter was 

 completely filled with manure which was scattered over the floor 

 toward the stanchions. 



The condition of the cows is well illustrated by figure 7. Their 

 flanks were caked with manure, but the visible dirt was removed from 

 the udders, which were washed before each milking. After having 

 been thoroughly washed with clean water and a cloth they were wiped 

 with another clean, damp cloth rinsed in clean water. The flanks of 

 the cows, which were liable to be rubbed by the milker's arm, also 

 were kept clean. 



During the period from November 10 to 21, 1915, 18 samples of 

 milk were examined from the open and 23 samples from the small-top 

 pail. The results in Table 3 show that the average number of bac- 

 teria in milk from the open pail was 6,166 bacteria per cubic centi- 

 meter, compared with 2,886 from the small-top pail. 



In the experiment 12 samples of milk were drawn directly from 

 the udder into sterile tubes at about the middle of the milking. The 

 average count of the milk from the four cows was 987 bacteria per 

 cubic centimeter. The difference between that average and the aver- 

 age in the milk from the open pail is 5,179, which represents the 

 number of bacteria per cubic centimeter introduced through external 

 contamination. The average number of bacteria per cubic centimeter 

 of 23 samples from the small-top pail was 2,886 ; subtracting 987 from 

 the count, the remainder, 1,889 bacteria per cubic centimeter, repre- 

 sents the number added through external contamination. 



Table 3. 



-Bacteria per cubic centimeter in dual samples of fresh milk produced 

 under conditions described in Experiment No. 3. 



Date. 



Sample 

 No. 



Open 

 pail. 



Small- 

 top pail. 



Date. 



Sample 

 No. 



Open 

 pail. 



Small- 

 top paiL 



1915. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 



15 



3,500 

 38,000 

 1,700 

 2,100 

 11,200 

 4,300 

 2,800 

 5,100 

 2,000 



2,400 

 3,100 

 2,400 

 4,300 

 1,500 

 1,800 

 1,000 

 2,900 

 2,700 

 1.200 

 2,700 

 2,800 

 2,100 

 2,000 

 3,800 



1915. 



16 

 17 

 18 

 19 

 20 

 21 

 22 

 23 





4,500 

 4,300 







3,600 





Nov. 20, p. m 



1,900 





Nov. 22, a. m 



5,600 



2,600 





Nov. 22, p. m 



5,000 





Nov. 23, a. m 



8,500 



4,103 







2,703 





Nov. 24, a. m 



2,800 



4, COD 





Average of milk 









6,166 



987 







3,200 

 i,700 

 4,000 

 3,500 

 6,200 



2,886 





Average of 12 









987 















5,179 



1,8C9 













The results show that when the udders were washed clean and the 

 small rtop, sterilized pail is used it is possible to produce milk of a 

 bacterial count closely corresponding to the number found in milk 



