SIGNIFICANCE OF COLON COUNT IN MILK. 



25 



hours at the same temperature the average count was about 205,- 

 000,000. The difference in the rate of growth of organisms of the 

 colon-aerogenes group at this temperature seems to vary somewhat 

 with the amount of initial contamination, as is shown by the colon 

 counts of the fresh milk and after 6 and 24 hours. Further obser- 

 vation of Table 14 shows that when the milk was held at 50° F. 

 (10° C.) there was little or no increase over the count in the fresh 

 milk. There are, however, a few samples which show a distinct 

 growth. 



Table 14. — Influence of conditions of production on the subsequent increase of organisms 



of the colon-aerogenes group. 







Total 



Colon count. 1 











Sample 

 No. 



Conditions. 



count in 

 fresh 





Held 6 

 hours at 



86° F. 

 (30° CO. 



Held 24 hours at — 







milk. 



Fresh. 















50° F. 

 (10° C). 



86° F. 

 (30° C). 



1 





f 27,000 







200 







290,000,000 



2 





58,000 



• 100 



400 







294,000,000 



3 





54,000 



100 







100 



126,000,000 



4 





83, 000 







100 







11,900,000 



5 





28, 000 















550,000 



6 





96, 000 















14,200,000 



7 





11, 800 















38,000,000 



8 





39, 000 







100 







2,400,000 



9 





21,600 















1,700,000 



10 





12, 400 















5,300,000 



11 



Barn dirty, cleaned twice a week; 



10, 200 







100 







139,000,000 



12 



utensils sterilized. 



22, 000 















11, 500,- 000 



13 





12, 500 















1, 100, 000 



14 





42, 000 



100 











250, 000, 000 



15 





16, 400 







( 2 ) 







6,300,000 



16 





22, 800 







( 2 ) 







42,000,000 



17 





24, 000 







( 2 ) 







12,400,000 



18 





37, 000 







( 2 ) 







17, 600, 000 



19 





13, 500 







( 2 ) 



300 



8,600,000 



20 





57, 000 







( 2 ) 







54,000,000 



21 





14,200 



400 



( 2 ) 



100 



37,000,000 



22 





l 15, 500 







( 2 ) 







28, 600, 000 



Avt 



>rage 



32,477 



1 



63,279,545 







1 





< 1,320,000 















60,000,000 



2 





790, 000 







400 



100 



450,000,000 



3 





1,600,000 















1, 900, 000 



4 





295,000 







500 







330,000,000 



5 





1,940,000 







200 







2,800,000 



6 





690, 000 



100 



300 







7,500,000 



7 





1.310,000 







1,400 







650,000 



8 





520,000 



100 



4,500 







248,000,000 



9 





750, 000 















11,400,000 



10 





460, 000 



100 



2,600 







510,000,000 



11 





320,000 







( 2 ) 







9,400,000 



12 



13 

 14 



Barn dirty, cleaned twice a week; 

 • utensils washed immediately but 

 not sterilized. 



440, 000 

 180, 000 

 490, 000 



400 

 

 



( 2 ) 

 

 900 



800 







1,100 



260,000,000 

 46,000,000 

 285,000,000 



15 





318,000 







1,000 







210,000,000 



16 





497, 000 







1,200 



100 



480, 000, 000 



17 





580, 000 







( 2 ) 







174,000,000 



18 





440, 000 



200 



( 2 ) 



100 



216,000,000 



19 





780, 000 



100 



2,400 



100 



420,000,000 



20 





710, 000 



800 



46,000 



600 



525,000,000 



21 





590, 000 



100 



8,600 



( 2 ) 



580,000,000 



22 





310,000 



900 



41,000 



( 2 ) 



430,000,000 



23 





190, 000 







800 



100 



55,000,000 



24 





230,000 



300 



74,000 



15, 100 



400,000,000 



25 





182,000 







1,100 



. 100 



152,000,000 



26 





340,000 



900 



48, 000 



900 



244,000,000 



Ave 



rage 



625, 846 





10,677 





234,948,077 











1 indicates no organisms of the colon-aerogenes group in 1/100 of a cubic centimeter of milk. 

 3 No determinations made. 



