Electronic detection of oestrus in postpartum dairy cows: efficiency and accuracy of the DEC ® (showheat) system

Abstract

Cow oestrus detection rates are of major constraint to good reproductive performance in dairy herds and there is a need for heat detection aid. The DEC ® system is an electronic device that detects cows that stand to be mounted by a herd mate and provides a continuous monitoring of activity. Accuracy and efficiency of this system was evaluated from 30 Holstein cows. They were fitted on the fourth or fifth week post-partum with the DEC ® system which was left in place until confirmation of pregnancy. During the same period, visual observation (VO) for occurence of oestrus were conducted four times daily and blood samples collected weekly for progesterone determination. A blood sample was also collected each time a cow was detected in oestrus independent of the method used. Inferred from progesterone patterns a total of 96 ovulation/oestrus periods occurred; 34 were correctly detected by the DEC ® system, 66 by VO resulting in efficiencies of 35.4 and 68.8%, respectively ( P<0.001). All oestruses detected by the DEC ® were also detected by VO. Five cows, different for each method, were incorrectly detected in oestrus leading to accuracies of 87.2 and 93.0%, respectively, for the DEC ® system and for VO ( P<0.01).