Care and Management of Dairy Cattle 161 
is quite insignificant, especially when compared with the value of 
such records. The materials needed are a pair of scales, a hand 
Babcock tester with outfit, and a blank milk-sheet. 
Once each month the milk from each cow should be tested for 
the percentage of butter-fat. To do this, one should take a sample 
of the milk for two successive days. The sample need not be 
large, but the quantity should be in proportion to the flow. One- 
half pint saved from the two days’ milking is sufficient. This 
should be placed in a jar and covered to prevent evaporation. In 
warm weather it is necessary to put some sort of preservative 
into the milk, otherwise it will sour, and in that case cannot be 
tested. For each cow there should be a jar with her name pasted 
upon it, thus avoiding any possibility of getting the samples mixed. 
By placing the percentage of fat thus obtained on the record- 
sheet, one has a complete record of each animal each month. 
By multiplying the total milk by the per cent of fat, one gets 
the total amount of fat. This completes the record for the 
month. 
267. Value of milk-records. — The highest degree of success 
cannot be attained unless we know the production of each indi- 
vidual cow. In addition, such records serve a much larger use- 
fulness because they enable us to mate the animals more judiciously. 
Not only are the low-producers unprofitable in themselves, but 
in the absence of a record of their production, they are propagated, 
and their offspring in turn prove unprofitable. 
TESTING MILK FOR BUTTER-FAT q 
The materials needed in testing milk for butter-fat are a cen- 
trifugal tester, test-bottles, a 17.6 c.c. (cubic centimeter) pipette 
to measure the milk, a 17.5 ¢.c. acid measure, and sulfuric acid, 
all of which can be purchased for about five dollars from any dairy 
supply company (Fig. 65). They may be ordered of a hardware 
dealer. Sulfuric acid is sold at any drug store. 
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