An electronic device for detecting estrus that may be affixed to the tail-head area of a cow is described. This device permits the accurate determination of optimal breeding time, natural or artificial, based on mounting activity. The device includes a water resistant housing, within which is contained...http://www.google.com.tw/patents/US7083575?utm_source=gb-gplus-share專利 US7083575 - Electronic estrus detection device
