22 BULLETIN 356, U. S. DEPARTMENT OF AGEICULTUEE. 
milk and escape the observation of the producer. Bits of straw or 
hay an inch or an inch and a haK long have been found in the bottom 
of the bottle, and cow hairs are often found in the sediment, and 
occasionally bristles from brushes 
To avoid visible dirt in the milk and thus receive a high score on 
this pomt it is necessary to follow the rules for cleanliness laid down 
under the heading '^Bacteria." Sometimes the sediment is due to 
the fact that pails or bottles after being sterilized are allowed to 
stand uncovered. If there is any wind stirring, chaff, dust, etc., are 
almost sure to be blown into the pails or bottles and will thus appear 
as sediment in the milk. Coarse strainers should be avoided if the 
producer wishes to get all the fine dirt out of the milk. The best 
results in the past have probably been secured with the use of cotton 
as a straining medium. Various forms of cotton are on the market, 
some in bulk and some prepared in thin sheets especially for strain- 
ing. In the answers to questions on the production of milk for con- 
tests there does not seem to be any special advantage in milkmg 
on to a strainer over the milk pad. Unless the strainer cloth is 
changed when each cow is milked such a practice is liable to result 
in worse contamination than when the milk is simply milked into an 
open pail and then strained into the can. 
FAT AND SOLIDS NOT FAT. 
Except in occasional cases a normal milk having a fat content of 
4 per cent contains more than 8.7 per cent of solids not fat. In some 
contests several samples have been entered which apparently had 
been modified by the producer in the attempt to obtain a higher score 
on chemical composition. Milks testing 8 per cent of fat and over 
have been submitted. Fortunately, such an adulteration is very 
easily seen by the judges when the fat is compared with the solids 
not fat. The contestant who tries to improve upon nature in this 
manner often decreases, rather than increases, his score. Any milk 
containing as much as 4 per cent of fat receives a perfect score, so 
that an 8 per cent milk gets no higher score on fat than a 4 per cent 
milk. The result of adding cream to milk to bring it from a 4 per 
cent to an 8 per cent fat is to lower the proportion of solids not fat 
in the milk, so that the score on that item is sometimes cut consider- 
ably. In normal milk the solids not fat increase as the fat increases 
but not in the same ratio. In milk to which cream has been added, 
however, the fat increases and the solids not fat are decreased. 
To eliminate contact with aU unnecessary utensils some contest- 
ants have milked directly into the milk bottle. The fii'st part of the 
milk drawn from the cow is quite deficient in fat, while the very last 
of the milk runs high in that constituent. In order to have a normal 
