Quantifying the Approaching Behaviors for Interactions in Detecting Estrus of Breeding Cattle

In the management of beef cattle breeding, estrus detection is especially important for improving productivity. Generally, pedometers have been used since the past few decades to measure the increase in momentum, which is likely to occur during estrus. Cattle are known to be social animals which take unique actions such as the approaching or mounting other cattle during estrus. However, the sociality of cattle has not been focused much on detecting estrus accurately. In this paper, we propose the method to detect estrus in relation to the approaching behavior between cattle. We extract the approaching behaviorbased on position information from GPS devices attached to the cattle. Our method focuses on moving direction to detect even small approaching actions with which the momentum may not increase clearly. Furthermore, we conducted an experiment based on the records of artificial insemination to examine the efficiency of our method. As a result, we verified some cases with a distinctive characteristic related to approaching behavior, which occurred during the days when the pregnancy was confirmed from the artificial insemination records.