The relationship between eating time during the transition period and the intervals between calving and the first insemination, the number of inseminations and the expected calving interval.

Abstract

To investigate the relationship between eating time during the transition period and 1) intervals between calving and first insemination; 2) number of inseminations per pregnancy; and 3) expected calving interval of dairy cows 1264 cows were enrolled in this study. These cows were equipped with Nedap smart tag Neck sensors from 42 days (d) before and 28 d after parturition, which continuously measured the eating time during this period. A Cox proportional hazard model was used to perform analysis between these fertility variables and the feeding time. Greater differences in residual deviance ante partum resulted in a higher number of inseminations and a longer expected calving interval. Longer intervals between calving and first insemination, higher number of inseminations and longer expected calving interval were found because of greater differences in feeding time between d -2 and d 2. Furthermore, a difference in the probability of pregnancy was found in heifers in comparison to cows. Moreover analysis show that farm effects have an influence on all included fertility variables. The results of this study underline the important relationship between feeding time variables during the transition period and fertility variables after parturition. This study demonstrates, for the first time, that more residual deviance before parturition leads to a greater risk of reduced fertility in dairy cows.