PRODUCTION OF MILK OF LOW BACTERIAL CONTENT. 



55 



Table 26. — Summary of results shown in Tables 20 to 25 inclusive. 



AVERAGE NUMBER OF BACTERIA. 



Temperature. 



Condi- 

 tion. 



Fresh. 



24 hours. 



48 hours. 



72 hours. 



96 hours. 



Section 1. 

 40°F 



1 ! 



• 



4,295 

 39,082 

 136, 533 



4,138 



88,028 

 281, 646 



4,566 



121,864 

 538,775 



8,427 

 186,245 

 749,030 



19,693 



1,056,922 



852, 835 



50° F 



1 1 



4,295 

 39,082 

 130,533 



13,961 



177,437 



1,170,546 



127,727 



831,615 



13,662,115 



5,725,277 



1,761,458 



25,687,541 



39,490,625 

 13,079,166 





41,207,272 



60° F 



Section 2. 



40°F 



50° F 



60° F 



1 i 



1 3 



! • 



4,295 

 39,082 

 136,533 



f 4,295 

 \ 4,295 

 | 4,295 



1,587,333 



4,461,111 



24,673,571 



4,138 



13,961 



1,587,333 



33,011,111 



99,120,000 

 639, 884, 615 



4,566 



127,727 



33,011,111 



326,500,000 



633,375,000 



2,407,083,333 



8,247 



5,725,277 



326,500,000 



962,785,714 



1,355,650,000 

 5,346,666,666 



19^693 

 39,490,625 

 962,785,714 



40° F 



50° F 



60°F 



i • 



f 39,082 

 i 39,082 

 | 39,082 



88, 028 



177,437 



4,461,111 



121,864 



831,615 



99,120,000 



186,245 



1,731,875 



633,375,000 



1,056,922 



13,097,166 



1,355,650,000 



40°F..! 



50°F 



60°F 



i ■ 



f 136,533 

 i 136,533 

 | 136,533 



281,646 



1,170,546 



24,673,571 



538,775 

 13,662,115 

 639,884,615 



749,030 



25,687,541 



2,407,083,333 



852,835 



41,207,272 



5,346,666,666 



RATIO OF GROWTH. 



50° F. 



50° F. 



F. 



F. 

 F. 



F. 

 F. 



50° F. 



10° F. 

 50° F. 

 50° F. 



1.25 

 2.40 

 2.47 



3.34 



6.70 

 14.68 



398. 60 

 351. 00 

 759. 90 



1.25 



3.34 



398.60 



2.40 



6.70 



351. 00 



2.47 



14.68 



759. 90 



1.21 



3.80 

 4,62 



31.07 

 24.30 

 137.94 



8,772.10 



6,114.80 



25,308.00 



1.21 



31.07 



8,772.10 



3.80 



24.30 



6,114.80 



4.62 



137. 94 



25,308.00 



2.66 

 4.40 

 10.19 



1,464.70 



86.00 



498. 06 



79, 809. 50 

 24,990.10 

 61,527.20 



2.66 



1,464.70 



79,809.50 



4.40 



86.00 



24,990.10 



10.19 



498. 06 



61,527.20 



5.10 

 22.10 

 11.99 



9,629.60 



612. 30 



1,385.06 



288,231.80 

 73, 920. 80 

 160, 873. 60 



5.10 



9,629.60 



288,231.80 



22. 10 



612. 30 



73,920.80 



11.99 



1,385. C6 

 160,873.60 



The effect of low temperature on the bacterial growth in any one of 

 the grades of milk demands special attention. From section 2 of 

 Table 26, it is evident that even if milk when fresh shows a low 

 bacterial count the number of bacteria will be high if it is held at a 

 high temperature. For example, milk with an average count of ap- 

 proximately 4,000 when held 24 hours at 4.4° C. (40° F.) showed ap- 

 proximately the same count. At 10° C. (50° F.) the count was about 

 13,000, while at 15.5° C. (60° F.) the average was about 1,500,000. 

 The results show in every case the great value of holding milk at 10° 

 C. (50° F.) rather than 15.5° C. (60° F.) 



It is realized that night's milk is generally held on the farm for 

 periods of from 12 to 15 hours before delivery; it is, therefore, im- 

 portant to know what bacterial increase will occur in milk held about 

 that period of time. In order to obtain data on the subject, samples 

 of milk produced under clean conditions in sterilized utensils and also 



