20 DAIRYING 



more than one per cent may be noticed in the milk of a cow from 

 day to day, or between the two milkings of one day. Such varia- 

 tion may tend to equalize each other and a milking of unusual 

 richness is generally followed by exceptionally thin milk. 



164. Nearly every kind of a variation has been noticed in the 

 amount and the richness of some cows' milk from one milking to 

 another, but a sudden drop or an exceptional increase in the weight 

 of milk given at one milking does not necessarily indicate that the 

 larger quantity will be thinner and the smaller amount richer than 

 the average test of that cow's milk. There is no uniform relation 

 between quantity and quality of milk from one milking to another. 



165. The test or per cent, of fat in a cow's milk from day to 

 day furnishes not only a means of calculating her value as a pro- 

 ducer of butter, but it may serve to show the physical condition of 

 the cow, as there is usually a good reason for a sudden change in the 

 richness of the milk from one milking to another. This was well 

 illustrated in the dairy cow tests conducted during the Columbian 

 Exposition or World's Fair held at Chicago in 1893. The milk 

 of each cow was weighed and a sample of each milking tested. I 

 well remember how keenly the test s'heets were watched every day 

 by the superintendents of the different herds of cows. If the 

 per cent of fat in the milk of any one cow showed a sudden increase 

 or a decrease, that cow was immediately examined, her tempetature 

 taken and questions asked about her treatment as to whether she 

 had broken loose in the night or anything whatever had happened 

 to her between milkings, that would help to explain the variation, 

 as the managers had learned that by watching the tests of a 

 cow's milk they could judge of her physical condition in much the 

 same way as a physician gets information about a patient's health 

 by feeling of his pulse. The cows in these World's Fair tests, 

 were very highly fed and on that -account not strictly comparable 

 with many cows on the farm, but the relation between a cow's 

 health, her treatment, etc., and the daily variation in the test 

 of her milk is undoubtedly a natural characteristic and of much 

 greater significance with some cows than with others. 



