11 THE SOURCES OF BACTERIA IN MILK 21 



pail. All the experiments were carried out in the cowsheds. 

 The following results were obtained : 



The influence of cleaning the udders is also shown by the 

 diminished number of bacteria in the milk. An average of 

 thirteen experiments at the Storrs Station ^ showed the 

 following results : 



Bacteria in milk from unwiped udders = 7058 per c.c. 

 „ „ wiped ,, =716 „ 



Decrease due to wiping =6342 „ 



(b) jSTumerous investigators have shown the presence of 

 bacteria in large numbers in the air of cowsheds. The dusty 

 floors, the usual presence of hay and other feeding -stuffs, 

 combined with the frequent movement, all renders bacterial 

 pollution of the air constant. Orr, for example, exposed plates 

 containing agar in cowsheds for 5 minutes during milking, 

 with the following results, the numbers being calculated as 

 falling on the surface of a twelve-inch pail. At the end of 

 96 hours at 20° C, the plates were counted and the numbers 

 calculated. The following results were obtained in the five 

 experiments: A =3456 and 3600; B = 4500; C = 3375 

 and 4185; D = 1260; E=2068 and 2700. 



1 Bulletin No. 42, Storrs Kvpcrimf.nt Station. 



