THE COST OF CATTLE 35 



AGES OF COWS IN COW-TESTING ASSOCIATIONS — C(7»fo-««e<i 



two years, while others for various reasons do not have them 

 come into the herd until older. 



1,916 X 2 = 3,832 

 674 X 3 = 2,022 



S,8S4 

 S,8s4 divided by 2,590 = 2.26 



The average age of entry into the herd is thus given as 2j 

 years. But it is customary to consider an animal two until 

 it is three years old; in some cases the nearest whole number 

 is given as the age. The average, therefore, of the two-year-old 

 heifers will be 2I and the three-year-old heifers 3I years old 

 at entry, so one-half year must be added, giving an average 

 age at entry into the herd of af years. In the table below 

 the ages are given in whole numbers. The number of three- 

 year-old heifers, for example, is 2,353, but these are really 3I 

 on the average, and the average age at exit between 3I and 

 4I would occur at four years. 



