292 



MILK 



NUMBER AND KINDS OF BACTERIA IN GRAIN FEEDS, SAWDUST, AND DRIED BLOOD 



Kind of 

 Sample. material.' 



1 Cottonseed meal 



2 Cottonseed meal 



3 Cottonseed meal 



4 Gluten 



5 Gluten 



6 Gluten 



7 Cornmeal 



8 Bran 



9 Dried blood 



10 Moist sawdust 



Liquefiers. 

 45,000 



1,800 



200,000 

 1,300 



Miscel- 



laneous. 



2,410,000 



29,500 



1,210,000 

 382,700 



On grain the percentage of acid-forming bacteria is twice as 

 great as on hay, while liquefiers are present in only half the num- 

 bers. Bacterium lactis acidi was found in cornmeal only. 



Flies are almost constantly present in cow stables during 

 the warm season. No matter how efficiently windows and doors 



Fig. 100. Showing construction of windows to facilitate screening and 



ventilating. 



are screened, it seems practically impossible to exclude the pests 

 completely. When cows leave the stable or return, the time dur- 

 ing which the doors have to remain open is long enough to admit 

 flies which follow the animals. Furthermore, flies are always 

 attracted to cattle, and large numbers enter the stable with them 

 (Fig. 100). 



Whether flies contribute to dust in the stable air is not -cer- 

 tain, although it seems reasonable to assume that they do in a 

 measure. However, flies frequently drop into the milk and then 

 the bacteria and the dust which they carry contribute to the 

 germ content of the milk. The fly constitutes a particular men- 

 ace, since it visits everywhere where filth is present. Flies may 



