44 



DAIRY FARMING 



well for her entire lifetime. A cow that is a small pro- 

 ducer by inheritance remains so year after year. The aver- 

 age yearly records in Table 11, selected, f rom many kept by 

 the writer for a number of cows for a term of years, indicate 

 this fact. Some variation occurs, but Table 11 shows that 



TABLE 11. YIELD OF BUTTER-FAT OF DIFFERENT INDIVIDUALS 

 BY YEARS IN POUNDS 



the good cows were good producers year after year, while 

 the inferior ones remained poor just as regularly. Occasion- 

 ally a cow has a poor year because she is out of condition, 

 but normally the results will be uniform when the feed and 

 care are the same. 



37. Extent of Variation of Individuals. An abundance 

 of data has been gathered within recent years to make it 

 plain that the variation of individuals as milk producers 

 is the greatest single factor in the success of the dairy. 

 The Connecticut Experiment Station found the five most 

 profitable in their herd were fed a year at a cost of $56.54 

 each, while the five poorest consumed feed worth $52.02. 

 The best five averaged 304 pounds of fat for the year, and 

 the poorest five 189 pounds. One group lacked $4.09 per 

 cow of paying for their feed. The other group gave $26.91 

 per cow above the cost of feed. For $4.52 in additional feed 



