Advance managemental tools to improve oestrus detection in dairy cattle

Herd reproductive performance depends on cows being accurately detected in heat and achieving adequate conception rates, inadequate heat detection has been identified as a major limit to herd reproductive performance over many years. To achieve good estrus detection, many factors have to be taken into account. On one hand a cow has to express estrus and on the other hand the farmer has to detect it. Combined action of several hormones causes physiological changes that lead to ovulation and an environment in the uterus that allows sperm to fertilize the egg. Besides these internal actions, a number of external changes can be observed. When using visual observations, time of the day and time spend on observation have a great impact on detection rates. Many devices are available to aid in estrus detection, such as pedometers, mount devices, temperature, and hormone measurements. Activity measurements are an important device for oestrus detection, but additional visual observations and the use of a cow calendar are necessary for sufficiently high detection rates. A combination of several estrus detection aids might give the best results in terms of estrus detection efficiency.