108 THE COW 



rather careful studies in New York and Minnesota 

 covering some thousands of cows indicate that the 

 average individual reaches an age of only between 

 eight and nine years. This figure does not mean 

 that cows die at this average age but rather it 

 represents the age at which they are removed from 

 the herd. Low-grade beef rather than natural 

 death is the fate of most cows. Inasmuch as a 

 cow must be at least two years old before she 

 "comes in," her actual period of usefulness does 

 not average more than seven years. It also means 

 that for each seven cows in the herd it will be 

 necessary each year to raise at least one calf to 

 take their place. There is really a rather rapid 

 shift of our bovine population. 



It should be remembered that these estimates 

 are the average for a large number of dairies, but 

 it does not follow that the same will be true on 

 any particular farm. The number of cows re- 

 moved from the herd will vary widely with cir- 

 cumstances and with the policy pursued, but in 

 general the more active and enterprising owners 

 will have the largest "turn-over" of cows because 

 they will be more energetic and persistent in 

 culling out undesirable individuals and will not 

 wait until a cow reaches extreme age before dis- 

 posing of her. 



There are a number of reasons why some 14 per 

 cent of our dairy cows must be replaced each year. 

 Disease and accident always take their toll, but 



