22 



BULLETIN" 642, tT. S. DEPARTMENT OF AGRICTLTrRE. 



raise the average greatly. The figures are of interest because with 

 similar barn conditions, dirty cows, and the manure removed 

 ■weekly, practically the same average number of bacteria were intro- 

 duced at periods of time which were about sis months apart. The 

 results again show that the number of bacteria introduced through 

 manure was not so large as had been expected. 



An examination of Table 6 shows the value of the small-top pail, 

 which is most strikingly shown in graphic form in figure 13. 



i 5 i 



Fig. 13. — Bacterial content of milk from sterilized small-top and open pails during 



Experiment No. 5. 



EXPERIMENT NO. 6. (COWS AND FLOORS DIRTY, MANURE REMOVED WEEKLY, 

 UTENSILS NOT STERILIZED.; 



The conditions of this experiment were similar to those of Ex- 

 periment Xo. 1. Table 7. covering the period from May 8 to 31, 

 1910. shows the average count of 36 samples of milk from the 

 small-top pail to be 111,197, compared with 153.905 bacteria per 

 cubic centimeter for the open pail. A comparison of the averages 

 with those in Experiment Xo. 1, results of which are given in Table 

 1, shows that the counts in the latter experiment were considerably 

 higher, which may be explained by the variable bacterial content 

 of unsterilized utensils. 



