Testing Milk on the Farm. 133 



cow's milk. A composite sample (see 175) taken from 

 four or more successive milkings will more nearly repre- 

 sent the quality of the milk which a cow produces at the 

 time of sampling. 



157. The variations that may occur in testing the milk 

 of single cows, are illustrated by the following figures 

 obtained in an experiment made at the Illinois experi- 

 ment station, 1 in which the milk of each of six cows was 

 weighed and analyzed daily during the whole period of 

 lactation. Among the cows were pure-bred Jerseys, 

 Shorthorns and Holsteins, the cows being from three to 

 eight years of age and varying in weight from 850 to 

 1350 Ibs. During a period of two months of the year, 

 the cows were fed a heavy grain ration consisting of 12 

 Ibs. of corn and cob meal, six Ibs. of wheat bran, and six 

 Ibs of linseed meal, per day per head. This system of 

 feeding was tried for the purpose of increasing, if possi- 

 ble, the richness of the milk. The influence of this 

 heavy grain feed, as well as that of the first pasture 

 grass feed, on the quality and the quantity of the milk 

 produced is shown in the following table, which gives 

 the complete average data for one of the cows (No. 3). 

 The records of the other cows are given in the publica- 

 tion referred to; they were similar to the one here given 

 in so far as variations in quality are concerned. 



i Bulletin No. 24. 



