THE RELATIONSHIP OF THE INTERVAL FROM BREEDING TO UTERINE PALPATION FOR PREGNANCY DIAGNOSIS WITH CALVING OUTCOMES IN HOLSTEIN COWS

This study used data collected prospectively at 32 dairy herds to exam ine the effect of interval from breeding to uterine palpation for preg nancy diagnosis on calving interval and likelihood of calving. Multiva riable statistical models were used to control for other factors that were significantly associated with the outcomes of interest. Cows diag nosed pregnant from 30 to 36 d post breeding had 2-wk longer calving i ntervals than cows palpated at later intervals. The interval from bree ding until a cow was diagnosed open had a significant positive associa tion with the calving interval. The interval to palpation was not asso ciated with the probability of remaining in the herd to calve when con trolling for the effects of herd, season of freshening, number of serv ices, days to first service and mature equivalent milk production. Amo ng cows diagnosed pregnant, 3.4% subsequently were bred and 1.5% were diagnosed open by palpation at a later date. About 5% of the cows diag nosed open calved at a time consistent with being pregnant when the di agnosis was made.