PROBLEM TO BE SOLVED: To provide a method for detecting the estrus of cattle by which the starting period of the estrus per cattle can accurately be detected.SOLUTION: The estrus is decided when an activity difference is a threshold value or above by paying attention to the activity time of the cattle detecting a signal continuation for a prescribed time or more set beforehand from signals of a motion sensor for detecting the movement of the cattle built in a tag mounted on a neck of the cattle converting the duration of the detected signal into each numerical value of units of the prescribed time obtaining activity numbers accumulating the activity numbers for each unit time computing the activity numbers for the unit time which is the activity time of the cattle computing each average activity number that is the average value of the activity numbers for the unit time in each time zone till the regulated activity time indicating the range of the time zone in retrospect to the past and each average standard activity number which is the average value of the average activity numbers in the same time zone as the latest activity number for the unit time in each day till the regulated number of days of activity indicating the range of the number of days in retrospect to the past subtracting the average standard activity number from the average activity number and computing the activity difference.COPYRIGHT: (C)2012,JPO&INPIT【課題】牛毎の発情開始時期を正確に検知することが可能な牛の発情検知方法を提供すること。【解決手段】牛の活動時間に着目して、牛の首に装着したタグに内蔵した牛の動きを検出するモーションセンサの信号から、前もって設定した所定時間以上継続した信号を検出し、検出した信号の継続時間を前記所定時間単位の数値に変換して活動数を取得し、前記活動数を単位時間毎に累積して、牛の活動時間である単位時間活動数を算出し、過去に遡る時間帯の範囲を示す規定活動時間までの各時間帯における単位時間活動数の平均値である平均活動数と、過去に遡る日数の範囲を示す規定活動日数までの各日における最新の単位時間活動数と同一の時間帯における前記平均活動数の平均値である平均標準活動数とを算出し、前記平均活動数から前記平均標準活動数を引いて活動差を算出して、前記活動差が閾値以上のときに発情と判断する。【選択図】図2
