MILK PRODUCTION 



473 



563. Influence on course of lactation. That individuality 

 plays an important part in determining the rate at which the 

 milk yield falls off with advancing lactation is shown more 

 specifically in a subsequent paragraph (568). 



564. Influence on composition of milk. It is a matter of 

 common observation that cows vary as regards the richness 

 of their milk, that is, as regards the amount of cream or butter 

 which can be obtained from a given weight of milk. Various 

 breed tests at experiment stations have served to define more 

 exactly the influence of individuality and breed upon the com- 

 position of milk. The results cited in Table 1 24 are intended 

 to illustrate this influence and not primarily to compare dif- 

 ferent breeds. The table shows the averages of the results ob- 

 tained at three different experiment stations 1 for several breeds 

 in tests covering periods of time ranging from eight months to 

 two years. The results from each station are given weight 

 in the average in proportion to the number of cows under 

 test, and the average results are arranged in the order of the 

 fat content of the milk. 



TABLE 124. AVERAGE COMPOSITION OF MILK OF DIFFERENT BREEDS 



Fat is evidently the most variable ingredient of milk, its 

 maximum exceeding its minimum in these averages by more 

 than 50 per cent. Along with the increase of fat there is 



1 Maine Expt. Sta., Rpt. 1890, p. 29 ; New Jersey Expt. Sta., Rpt. 1890, pp. 223- 

 224; New York (Geneva) Expt. Sta., Rpt. 1891, pp. 94-104. 



