Dairy operation management practices and herd milk production.

A national US survey collected data on herd milk production and management of Holstein herds. Step-wise selection identified management practices that were related to herd milk production using only operations that calculated herd milk production as well as using data from all operations. 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 production than operations with no registered cattle. Dairy operations that reported a mean BW > 545 kg at first calving had higher mean milk production than operations with a mean BW < or = 545 kg at first calving. Operations that reported mean age at first calving < 27 mo had higher mean milk production than operations with a mean age > or = 27 mo at first calving. In addition, use of the following management practices was associated with higher rolling herd average milk production: calves born in individual areas in buildings, calves hand-fed first colostrum, starter grain fed to preweaned calves, ionophores fed to heifers from birth to first calving, DHIA record-keeping system used, computerized records, and no new cattle introduced in the previous 12 mo.