PRODUCTION AND REPRODUCTIVE RESPONSES TO USE OF DAIRYMAN - A MANAGEMENT-INFORMATION-SYSTEM FOR NEW-ZEALAND DAIRY HERDS

To assess the benefits of on-farm use of a computerized management inf ormation system (DairyMAN, Department of Veterinary Clinical Science, Massey University, Palmerston North, New Zealand) on seasonally calvin g herds of New Zealand, data for 144 herds using this system were comp ared with a stratified random sample of 294 herds using only the centr alized National Dairy Database system during the season 1993 to 1994. Demographic, reproductive performance, and milk yield indices were com pared. Herds using DairyMAN had superior reproductive outcomes, measur ed as a higher percentage (+8.4%) of cows calving during the desired s easonal period (critical in this seasonal system) and a higher percent age of cows (+9.7%) mated at the optimal time to achieve a concentrate d calving in the following year. Multiple analysis of covariance was u sed to differentiate effects. The superior performance was not associa ted with differences in some of the more commonly used reproductive in dices (efficiency of estrus detection, first service nonreturn rate, a nd pregnancy rate), but the data used in the study do not accurately r eflect true performance. Herds using Dairy-MAN had more information on breeding performance because pregnancy data were available and natura l breedings were recorded for a longer period. With cows of equivalent genetic merit, herds using DairyMAN produced more milk (+1.2 L/d per cow) indicating that users achieved better management of the herd thro ugh improved attention to managerial details. This improved production was associated with the adoption of DairyMAN but is not shown by this study to be a direct consequence of it. DairyMAN user herds were larg er (245 cows) than were herds not using the system (181 cows), but thi s difference did not significantly affect the various outcomes measure d.