176 DAIRY FARMING 



are usually about the same at each milking. If the intervals 

 are not equal, the larger yield of milk and a lower percentage 

 of fat follow the longer interval. When the milking is done 

 three times or more daily, the variation in fat content is 

 generally considerable, even though the intervals between 

 milking are equal. As a rule, the milk drawn near the noon 

 hour has the highest fat content. Where the composition 

 is varied by unequal intervals, the variation is confined 

 mostly to the fat. 



165. Fore Milk and Strippings. The first milk drawn from 

 the cow contains a low percentage of fat, while the last is sev- 

 eral times richer in this constituent. The first milk as a rule 

 contains from 1.5 to 2.5 per cent, while the strippings range 

 from 5 to 10 per cent. The other constituents of the milk 

 are practically the same in all parts of the milking. Numer- 

 ous variations occur from day to day that cannot be ex- 

 plained by any of the 'factors described. A single sample of 

 milk from a cow may be entirely misleading. 



166. Effect of Feed. The error is often made of assuming 

 that the richness of milk varies with the feed. While it 

 is possible under certain conditions to make a variation of 

 possibly 0.2 to 0.4 per cent by giving certain feeds, it is 

 only under conditions so abnormal that it is of scientific 

 interest only and has no practical bearing. As far as the 

 ordinary practice is concerned, the feed has no influence 

 upon the richness of the milk. If a certain cow averages 

 3.4 per cent fat for a year, no one knows how to feed her to 

 make her milk average 4.0 per cent for the following year. 

 The richness of a cow's milk is fixed by heredity and cannot be 

 permanently changed by any means. It is a well-known fact, 

 however, that a cow in a high state of flesh at time of calving 

 gives richer milk for a short time than does one thin in flesh. 



