34 PROFITABLE DAIRYING 



If the milk stands for even a minute after being 

 mixed, the sample will not be accurate, so rap- 

 idly do the fat globules tend to come to the 

 surface. 



If a single cow is to be tested, she must first 

 be milked perfectly dry, then all of her milk 

 must be thoroughly mixed and a portion of this 

 taken for testing. It is important to have all 

 the cow's milk, as the fat content tends to in- 

 crease during the process of milking, the strip- 

 pings being much richer than the foremilk; often 

 the foremilk will test less than one per cent, 

 and the strippings over ten per cent fat. For 

 this reason the sample can never be milked into 

 a separate vessel if accurate results are desired, 

 but must be taken from the whole amount of 

 milk, and then only after a thorough stirring. 



If a small sample is to be tested, this too must 

 be thoroughly mixed before the final sample is 

 taken in the pipette. If more than one test is to 

 be made from the same sample, the sample should 

 be mixed each time before being drawn into the 

 pipette. Thorough mixing is the most important 

 part of sampling, and good sampling is one of the 

 most important points to be observed in making 

 a correct test. 



2. Filling the test bottle. When the sample 

 has been thoroughly mixed, the milk should be 

 drawn into the pipette by suction with the mouth 



