DAIRY OPERATION MANAGEMENT-PRACTICES AND HERD MILK-PRODUCTION

A national US survey collected data on herd milk production and manage ment of Holstein herds. Stepwise selection identified management pract ices that were related to herd milk production using only operations t hat calculated herd milk production as well as using data from all ope rations. Results were similar. Milk production was highest in the West . Operations with <100 dairy cows had lower production than did larger operations. Operations with >25% registered cattle had higher product ion than operations with no registered cattle. Dairy operations that r eported a mean BW >545 kg at first calving had higher mean milk produc tion than operations with a mean BW less than or equal to 545 kg at fi rst calving. Operations that reported mean age at first calving less t han or equal to 27 mo had higher mean milk production than operations with a mean age >27 mo at first calving. In addition, use of the follo wing management practices was associated with higher rolling herd aver age milk production: calves born in individual areas in buildings, cal ves hand-fed first colostrum, starter grain fed to preweaned calves, i onophores fed to heifers from birth to first calving, DHIA record-keep ing system used, computerized records, and no new cattle introduced in the previous 12 mo.