Testing Milk on the Farm. 147 



is factory data as to the total production of milk and 

 butter fat of a cow may be obtained by making correct 

 weighings and tests of her full day's milk once every 

 thirty days. 



167. When to test a cow. The Vermont experi- 

 ment station for several years made a special study of 

 the question when a cow should be tested in order to 

 give a correct idea of the whole year's production, when 

 only one or two tests are to be made during the lacta- 

 tion period. 1 The results obtained may be briefly sum- 

 marized as follows: 



a. As to quality of milk produced. If two tests of 

 each cow ? s milk are to be made during the same lacta- 

 tion period, it is recommended to take composite sam- 

 ples at the intervals given below. 



If only one test is to be made, approximately correct 

 - Its may be obtained by testing the milk during the 

 h month from calving, in case of spring cows ; dur- 

 ing the third to fifth month in case of summer-calving 

 3, and during the fifth to seventh month for fall- 

 calving cows. 



In all cases composite samples of the milk for at least 

 four days should be taken (169). "The test of a single 

 sample, drawn from a single milking or day, will not of 

 necessity, or indeed usually, give trustworthy results." 



1 Sixth report, 1S81>. p. lOtf: Ninth report. 1886, p. 17& 



