Vaginal temperature measurement by a wireless sensor for predicting the onset of calving in Japanese Black cows.

We evaluated the utility of the continuous measurement of vaginal temperature by a wireless sensor and wireless connection for predicting the onset of calving and for clarifying the relationships among dystocia, calf conditions, and temperature changes at a commercial beef cattle farm in Japan. A total of 625 effective delivery data was collected. The temperature sensor inserted to the vagina on 7 days before the expected due date and collected the vaginal temperature every 5 min.