SANITARY MILK PRODUCTION 35 
The water of ponds and stagnant streams is especially 
dangerous. ‘Not only is such water injurious to the health 
of cows, but in wading into it, they become contaminated 
with numerous undesirable bacteria, some of which may 
later find their way into the milk. 
Strainers and Straining. Milk should be drawn so 
clean as to make it almost unnecessary to strain it. This 
Operation is frequently done under the delusion that so 
long as it removes all visible dirt the milk has been 
entirely purified. The real harm, however, that comes 
from hairs and dust particles dropping into the milk is 
not so much in the hairs and dust particles themselves 
as in the millions of bacteria which they carry with them. 
These bacteria are so small that no method of straining 
will remove them. Straining can not even remove all 
of the dirt, because some of it will go in solution. 
A good strainer consists of two thicknesses of cheese 
cloth with a layer of absorbent cotton between. The 
strainer is to be placed on thé can or vat into which the 
milk is to be strained and not on the milk pail. While 
a strainer like the above placed upon the milk pail, reduces 
the bacterial content slightly in the hands of careful milk- 
ers, it is believed that the slight advantage gained would 
be more than off-set by greater carelessness in milking 
especially might this be true with ignorant milkers who 
are apt to think that the strainer will make up for any 
carelessness on their part. A cheese cloth strainer on 
the milk pail is worse than useless with any kind of 
milker, 
New sterilized cotton must be used at each milking 
and the cloths must be thoroughly washed and sterilized. 
Like the cotton, it is best to use the cloth but once. 
Dust-Free Air; Great precaution should be taken not 
