40 



BULLETIN 642, U. S. DEPARTMENT OF AGRICULTURE. 



sterilizer was demonstrated to the farmers, who were then left 

 to operate it without further assistance. As the work was carried on 

 during the summer and the cows were in pasture most of the time, 



their udders were 

 always practically 

 free from visible 

 dirt ; therefore that 

 factor received no 

 further considera- 

 tion. 



At each milking 

 the milk was stirred 

 by means of a long, 

 sterile pipette, after 

 which samples were 

 taken from each can 

 and a composite 

 sample made, which 

 was immediately placed in ice water and plated within an hour and 

 a half. For a period of three weeks samples were taken at each 

 farm under the usual conditions (open pails, not sterilized) and for 

 the three weeks following, when small-top pails, sterilized, were in 

 operation. 



Table 18 shows the bacterial count of each sample obtained from 

 the night's milk, fresh, on each farm during the entire six weeks, also 



fe ill 



J 



1 



Fig. 19. — Interior of barn at farm Xo. 27. 



Fig. 20. — Interior of barn at farm No, 43. 



