226 ANNUAL REPORT OF THE Off. Dog. 



meiit station. Tlie results of analyses are useless and misleading if 

 obtained on poor samples. There is reason to believe that many do 

 not understand how easy it is to take an incorrect sample. 



The following directions for accurate sample taking are printed for 

 the information of the dairymen of the state. Copies will be sent 

 without charge to any address on application to the Experiment Sta- 

 tion, Burlington, Vt. 



1. To test indimdual cows . — Provide as many fruit jars (pints or 

 quarts) as there are cows to be tested. (Wide-mouthed bottles will 

 do if jars cannot be obtained. If used, they should have tight corks. 

 Narrow-mouthed bottles make accurate sampling difficult and often 

 impossible.) 



Label each jar. Into each put preservatives to keep the milk 

 sweet. (Use either formalin, sometimes called formaldehyde, about 

 20 to 30 drops; or corrosive sublimate, colored with analin red, about 

 ten grains; or potassium bichromate, not more than ten grains. 

 Formalin is preferable and non-poisonous, the other two are poisons 

 and should be handled carefully. These, or some one of these, may 

 be obtained at any drug store or at the local creamery.) 



At the first milking pour the entire milk of the cow back and forth 

 from one pail to another not less than three times and then at once 

 dip out approximately a gill (a gill cup on a long handle works well — 

 a small tea-cup will do) and pour into the jar. Close the jar and 

 keep it closed until the next milking. Proceed thus with each cow. 

 At the next milking repeat the operation, adding a second gill of re- 

 cently-poured milk from the first cow to the gill taken at the first 

 milking, and similarly with the other cows. Proceed thus for from 

 four to eight successive milkings, keeping the jar closed except when 

 putting in the milk. This makes what is known as the composite 

 sample, one which is much more trustworthy than a sample taken 

 from a single milking. If samples are to be transported, the last 

 sub-sample of each composite sample taken should be made to fill the 

 jar absolutely full to prevent churning while in transit. 



Cows vary considerably in the quality of their milk at different 

 stages of lactation. If only infrequent samples are taken, most 

 nearly accurate results (that is, such as will most closely indicate the 

 average quality for the year) will be usually obtained if samples are 

 taken approximately as follows: 



Cows calving in the spring: One composite sample six weeks and 

 another six and a half to seven and a half months after calving; or 

 two composite samples, taken about two weeks apart six months 

 after calving. 



Cows calving in the summer: One composite sample eight weeks 

 and another six to seven months after calving; or two composite sam- 

 ples, taken about two weeks apart, from three to five months after 

 calving. 



