Fertility before and after installation of Herd Navigator™

Abstract: The fertility of dairy cows is of great importance in order to maintain high production. The decline in fertility of dairy cows the latest decades can have several explanations. The large emphasis on high yielding cows and the negative genetic correlation between milk production and fertility traits could be one of the main factors for impaired fertility. To find heats and inseminate the cow at the right time is crucial to receive high conception rate. Delaval has, in corporation with FOSS, developed Herd Navigator which is a management program that measure four biological parameters in the milk; progesterone, betahydroxybutyrate, lactate dehydrogenase and urea. In this study the focus will be on progesterone which is a hormone produced by the corpus luteum. The concentration of this hormone indicates where the cow is in her estrus cycle. The study was performed on three Swedish and three Dutch farms where the parameters for fertility were compared one year before and one year after the installation of Herd Navigator. Calving interval, number of inseminations per pregnancy, conception rate, open days and days from calving to first insemination were analyzed. Unfortunately several inseminations were found to be missing in the data set before the installation of Herd Navigator. The fertility measures based on number of inseminations were therefore not reliable; however calving dates seemed to be complete reported. No significant differences in open days and calving interval before and after the installation of Herd Navigator could be found in this study. However, a significant reduction in number of days from calving to first insemination could be seen. There was also a tendency of a shorter calving interval on the Swedish farms after the installation. To get additional information of the practical experiences of Herd Navigator an interview with the farmers was made. They found that the measurements of progesterone were very helpful and time saving in order to find heats. It would be interesting to implement further and more comprehensive studies on a larger data set that include all inseminations. Moreover, it would be interesting to see what impact continuous measurements of progesterone will have on the reproduction performance.