Rate, Age, and Criteria for Disposal in a Herd of Registered Jersey Cattle

Reasons for disposal of dairy cattle from a registered Jersey herd established in 4887, noted for high production, on supervised herd test since ]929, and classified annually since 1938, were analyzed for the period, 1948 to October, ]963. Average size of the milking herd was 108.4 cows. Sixty-seven per cent of the 854 females, exclusive of free-martins, born during the period lived to enter the milking herd. Stillbirths and early post-natal mortality accounted for 23.3% of the disposals. Sterility, undesirable type and unthriftiness, and pedigree were the major reasons for disposal of heifers between six and 24 months of age, accounting for 42.7, 35.3, and 9.8% of the reasons for disposal in this age group, respectively.