Reproduction, Events and Management: Mating Management: Detection of Estrus

Estrus detection is one of the key components in fertility management programs on dairy farms. Low detection rate is strongly associated with poor fertility, long calving interval, intensive replacement of heifers, and reduced genetic progress, resulting in heavy economic losses. The goal of an estrus detection program is to identify estrus positively and accurately in all cycling cows with an ultimate goal to predict the time of ovulation, thus allowing for insemination that will maximize the opportunity for conception.In general, the market sorts out which technologies offer a competitive advantage and which do not. It includes technologies using pedometers, a pressure-sensing radiotelemetric system, electrical resistance, body temperature, and monitoring of milk progesterone levels. Most of the aids that have been developed are not reliable or sensitive enough to relieve the farmer from frequent visual observation of the herd. Combining technologies for simultaneous measurements of several physiological events associated specifically with the onset of estrus and ovulation time should provide more accurate predictions of the optimal time for insemination. New approaches are being developed to provide automated systems for estrus detection using remote-sensing technology, but the development of these new tools is in its infancy.