Abstract

If the mating start date (MSD) is incorrectly established through database monitoring, then several reproductive measures will also be incorrect in a seasonal calving dairy herd. The definition currently used by the InCalf Fertility Focus report is the first day withartificial breeding (AB) record(s) within a sequence of four of seven days with artificial breeding (AB) records (Method A). The objective was to compare this with alternative definitions to reduce the occasional incidence of incorrect MSD that have been encountered in these reports. The alternative definitions testedwere two consecutive and four out of seven days (Method B), one percent (Method C) and three consecutive days (Method D). The National Dairy Database was used to test these alternate definitions. Among 963 herds with less than 150 cows, the current definition of MSD was the most appropriate. Among 7,004 herds with greater than or equal to 150 cows, visual assessment indicated that a new definition was more accurate. This was that MSD be set as the first of two consecutive days when followed with four of the next seven days having recorded AB matings.

FE, Creagh, K Sanders, and LR McNaughton

Proceedings of the New Zealand Society of Animal Production, Volume 73, Hamilton, 79-82, 2013