232 MANUAL OF FARM ANIMALS 



The length of time required to weigh the milk and take 

 the sample will depend much on the activity of the one 

 doing the work. On the average it will require less than one- 

 half minute a day for each cow to weigh the milk and set the 

 weight down on the record-sheet. On the two consecutive 

 days that the samples are taken, it will require the same time 

 daily to the cow as weighing and making the record. Then an 

 hour or two once a month is all that is required to make the 

 Babcock test for percentage of fat. With this length of time, 

 one can obtain a reasonably accurate record of the performance 

 of every cow in his herd. 



Value of milk-records. — The highest degree of success 

 cannot be attained unless we know the production of each 

 individual cow. In addition, such records serve a much larger 

 usefulness 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 un- 

 profitable. 



TESTING MILK FOR BUTTER-FAT 



The materials needed in testing milk for butter-fat are a 

 centrifugal tester, test-bottles, a 17.6 c.c. (cubic centimeter) 

 pipette to measure the milk, a 17.5 c.c. acid measure, and sul- 

 furic acid, all of which can be purchased for about five dollars 

 from any dairy supply company (Fig. 77). They may be 

 ordered of a hardware dealer. Sulfuric acid is sold at any 

 drug store. 



Sampling the milk. — The milk to be tested should be 

 thoroughly mixed just before sampling. To do this, pour back 

 and forth between two vessels several times. With the pipette, 

 measure out 17.6 c.c. of milk and place in the test-bottle. To 

 do this, suck the milk up above the 17.6 c.c. mark. Quickly 

 place the index finger over the upper end of the pipette, then 



