Table 8. Estimated Livestock Numbers and Numbers of Heifers 

 Freshening per 1,000 Cows, New Hampshire, 1945-55 



^ "Livestock and Poultry on Farms and Ranches," January 1, Crop Reporting Board, Agricultural 

 Marketing Service, U.S.D.A. 



- Based on the Calf Crop Reports, Cro]) Reporting Board, Agricultural Marketing Service, U.S.D.A. and 

 the assumption that 49 percent of the total calves born are heifers. 



^ Based on 4 percent loss from sterility and 1 percent loss from death as the average age of the 

 heifers 1 to 2 years old is 18 months. 



Association cows, the annual rate of increase in the cow population is 

 101.8 cows per 1,000 cows. Over time, a farmer with 20 cows could make 

 2 additional replacements a year to upbreed his herd, assuming that the 

 replacements were superior to the cows in the herd. The point is that the 

 increase in the rate of culling of cows for herd improvement is very small. 



Incidence of Disease, Herd Life, Age at Disposal, and Life Expectancy 



A total of 3,078 cow-removal records was obtained for the period 1952 

 through 1954 from several New Hampshire Dairy Herd Improvement Asso- 

 ciations (Table 9). These records list each cow removed from an 

 Association member's herd and the reason for removal. The individual 

 removal records are also classified by years in the milking herd, 

 age at removal, and whether the cow was raised or purchased. Of 

 the total removals, 76 percent, or 2,347 cows, were raised. The remaining 

 24 percent, or 731 cows, were bought. The chief reason for disposal of 

 raised cows was for sale for dairy purposes. This amounted to about 33 

 percent of all disposals of raised cows. Low production ranked second; it 

 accounted for about 23 percent of the cows removed. Sterility and udder 

 trouble caused about 14 and 12 percent, respectively, of the cow removals. 

 These four reasons accounted for 87 percent of the removals of raised cows. 

 They also represented the four most important reasons for removal of 

 purchased cows. For purchased cows, however, low production accounted 

 for 27 percent of the removals and ranked first in importance. Sales for 

 dairy purposes accounted for 24 percent of the removals. Sterility and udder 

 trouble ranked the same as for raised cows and caused 17 and 15 percent, 

 respectively, of the removals. These four major reasons accounted for 83 

 percent of the disposal of purchased animals. ^'-^ 



19 The removal records for New Hampshire are similar to those reported for other 

 states. Appendix Table 1 shows a comparison of the several reasons for removal for 

 New Hampshire and several other states. Appendix Table 6 shows the effect of age 

 on percentage of cows removed for New Hampshire, Kansas, and Indiana. 



23 



