POINT OF VIEW ON LIVE-STOCK PROBLEMS 233 



years old or older. At the same time, there were 7,365,265 

 yearling heifers. This is one heifer for each 4.6 cows. 1 



Ten years before, there was one heifer for each 4.1 cows. 

 The change in date of the Census has some effect, but it 

 appears that the length of time that cows are kept has in- 

 creased, so that cows are now kept until they are a little 

 over 6 years old. Dairy cows are kept longer than beef 

 cows. 



On New York farms, there were 7 cows for each yearling 

 heifer in 1910, indicating that the average cow is probably 

 kept until she is between 8 and 9 years old. This also 

 agrees with the detailed study in Tompkins County. 



In Wisconsin, there was one yearling heifer for each 

 4.7 cows. In Iowa, there was one heifer for 3.6 cows. 

 As feed becomes more expensive cows are kept longer. 



As population increases, the dairy cows increase faster 

 than beef cows. During the ten years 1900 to 1910 dairy 

 cows increased 20 per cent and other cows only 2 per cent. 



153. Depreciation on horses. The depreciation on 

 animals that have no meat value is the same per cent re- 

 gardless of the value of the animals, provided the high- 

 priced animals live to the same age as the low-priced ones. 



By making a study of Census figures and the excess of 

 exports over imports, it appears that one colt is raised for 

 11.7 horses older than yearlings, in order to keep up the 

 supply of horses. On the average, two-year-old horses 

 may, therefore, be expected to live about 12 more years. 2 



1 If correction is made for the increasing number of cows, the difference 

 is not enough to change the ratio. Cows increased during the preceding 

 ten years at the rate of 391,857 per year, so that the number of heifers 

 will probably be enough to provide 34,054,051 cows. According to these 

 figures, the average cow is kept 4.6 years. 



2 In 1910, there were 20,370,477 horses older than yearlings (born 

 before 1909) in the United States. This includes horses in cities as well 



