| dc.description.abstract | This study is a part of a project called ‘Sense of sensors in transition management’. With sensors, there are 736 cows of 8 farms are pre- and postpartum followed and their behavior has been recorded. Many sensor data has been collected from January 2015 till September 2017, a total of 736 cows has been selected based on their calving date. The sensor data has been compared with the rectal examination and ultrasound results to determinate if the sensor-detected heat means also an ovulation. The algorithm for first heat has been calculated and is used for further investigation.
Of the 736 cows in the present study, 269 cows (36%) did have a first heat before 30 days postpartum and only 76 (10%) of these cows did have a first, second and third heat. A worrying result of this study is that on the eight farms, of 736 cows in total, 273 cows (37%) are completely acyclic in the first 70 days postpartum. Which means there is no heat detected in 37% of the cows with this sensors and this threshold, heat detected with the sensor is in this case not proving for an occurred ovulation. In this population of 736 Dutch dairy cows, the prevalence of metritis and cystic ovarian disease (COD) is also determined, which is 16.3% and 4.9%, respectively. First heat before or after 30 days postpartum has no influence on the prevalence of metritis and COD. | |
