SIGNIFICANCE OP COLON COUNT IN MILK. 



23 



Table 12. — Growth and frequency of organisms of colon-aerogenes group at 60° F. 



(15.6° C). 



Num- 

 ber of 



Conditions. 



Average 

 total 

 count. 



Average colon count. 



sam- 

 ples. 



Fresh. 



24 hours. 



20 



Barn clean, cows clean, 

 utensils sterilized 

 (A). 



Per c. c. 

 4,245 



Per C. C. 



100 per cent - in yiOO c. c. 



Per c. c. 

 66.6 per cent — . 

 33.4 per cent +. 

 Range, 400 to 76,000. 

 Average colon count, 14,083.! 



34 



Barn dirty, cleaned 

 once a week, cows 

 dirty, utensils ster- 

 ilized (B). 



38, 262 



94.1 percent — . 

 5.9 percent +. 

 Range, 100 to 300. 

 Average colon count, 200. 



31 per cent — . 

 69 per cent + . 

 Range, 1,000 to 510.000. 

 Average colon count, 79,175. 



23 



Same as B, but uten- 

 sils not sterilized. 



161,083 



95.6 per cent — . 



4.4 percent +. 



Average colon count, 400. 



33.3 percent — . 

 66.7 per cent +. 

 Range, 6,100 to 710,000. 

 Average colon count, 156,450. 



Num- 

 ber of 



Conditions. 



Average 

 total 

 count. 



Average colon count. 



sam- 

 ples. 



48 hours. 



72 hours. 



96 hours. 



20 



Barn clean, cows 

 clean ; utensils 

 sterilized (A). 



Per c. c. 

 4,245 



Per c. c. 

 50 percent — . 

 50 per cent -1- . 

 Range, 1,000 to 



840,000. 

 Average colon count, 



318,333. 



Per c. c. 

 35.3 per cent — . 

 64.7 percent +. 

 Range, 1,700 to 

 25,500,000. 



Average colon count, 

 5,506,518. 



Per c. c. 

 37.5 per cent — . 

 62.5 percent +. 

 Range, 4,000 to 



152,000,000. 

 Average colon count, 



27,288,900. 



34 



Barn dirty, cleaned 

 once a week, cows 

 dirty, utensils 

 sterilized (B). 



38, 262 



4.0 per cent — . 

 96.0 per cent + . 

 Range, 98,000 to 



21,600,000. 

 Average colon count, 



3,285,750. 



8.3 per cent — . 

 91.7 percent +. 

 Range, 900,000 to 



68,000,000. 

 Average colon count, 



18,786,364. 



100 per cen# + . 

 Range, 1,000,000, to 



66,000,000. 

 Average colon count, 



23,008,333. 



23 



Same as B, but 

 utensils not ster- 

 ilized. 



161, 083 



26.3 per cent — . 

 73.7 per cent +. 

 Range, 84,000 to 



4,300,000. 

 Average colon count, 



882,929. 



5.5 percent — . 

 94.5 per cent +. 

 Range, 64,000 to 



42,000,000. 

 Average colon count, 



4,579,117. 



100 per cent +. 

 Range, 115,000 to 



168,000,000. 

 Average colon count, 



15,600,611. 



1 Average colon count per cubic centimeter in samples showing them in 1/100 of a cubic centimeter and 

 over. 



When milk is held at higher temperatures the growth of organisms 

 of the colon-aerogenes group increases in rapidity, which is shown by 

 the results given in Table 13. Twenty samples of milk produced 

 under dirty conditions with unsterilized utensils were held at 50° F. 

 (10° C.) and 70° F. (21° C.) and the colon count determined in the 

 fresh milk and after holding for 24 hours. Although this milk was 

 produced under extremely filthy conditions, only 3 of the samples 

 when fresh showed organisms of the colon-aerogenes group in 1/100 

 of a cubic centimeter. This series contained the only sample of 

 fresh milk produced under normal conditions which showed a colon 

 count of over 2,000 per cubic centimeter. The results in this table 



