A06 MILK AND MILK PRODUCTS 
sterilizing of the milk vessels, or sometimes the presence of cows with 
infected udders. With propely cleaned and sterilized milk vessels 
and proper care in the farm and dairy the numbers of bacteria should 
not exceed 10,000, and may easily be brought down to 5000. Numbers 
beyond these in milk analyzed immediately after the milking may be 
regarded as an indication of unclean dairy methods, dirty and unsterile 
milking vessels, or to infected udders. Apart from infected udders the 
factors in dairying that most noticeably increase the bacteria count 
are unsterile milk vessels, unsterile strainers, unclean udders, and failure 
to cool the milk promptly. 
2. Tf the milk is properly cooled with ice the numbers should rot 
materially increase in five to seven hours. Communities within five to 
seven hours of their dairies should, if perfect conditions prevail, be able 
to obtain milk with nearly as low a count as above indicated. Hence, 
in such communities bacterial counts above these numbers should not 
be found in properly guarded milk. A count of 50,000 in such a com- 
munity is an indication cither of unsatisfactory dairy conditions or 
af failure to properly cool the milk during transpoitation. Night’s 
milk, if properly cooled, can also easily be brought within these limits 
if analyzed the next morning. A count of over 50,000 fer a community 
close to the dairies must be regarded as unsatisfactcry, and the number 
should approach the 10,000 mark for high-grade milk. In hot summer 
weather the difficulties of keeping low counts are greater, but even 
then they need not surpass 50,000 if the milk is properly cooled. 
3. “‘ Where milk must be a longer time in transportation from the 
dairy there will inevitably be an increase in bacteria, depending on the 
length of time and the temperature. Experience has shown, however, 
that even in these conditions the exesssively high numbers that have 
frequently been found in city milk are in reality duc to diseased udders, 
to dirty dairy conditions, to dirty and unsterile milk utensils, or culpable 
neglect of cooling. Moreover, such high bacterial counts at the ship- 
ping station are frequently traceable to a few dirty dairies whose milk 
with an abnormally high count contaminates the rest of the supply. 
Dirty shipping cans and warm temperatures in shipping are respon- 
sible for most of the high bacterial counts in city milk. Where the milk 
from healthy cows reaches the city within twenty-four hours, however, 
the number should not be over 100,000 in winter or 200,000 in summer, 
and numbers in excess of this may be regarded as due either to improper 
dairy conditions, dirty milk vessels, insufficient cooling or, perhaps, to 
diseased udders. In larger cities where much of the milk is forty-eight 
hours in reaching the city, higher numbers may naturally be expected; 
