Efficiency of Three Tools for Detecting Heat in Holstein Heifers

Abstract

The aim of this work was to determine the efficiency of three tools for heat detection in Holstein heifers. Thirty-four Holando heifers (synchronized in heat with two doses of Prostaglandin F2α, administered with an interval of 11 days) were evaluated. All the estrus behaviors (BEHAVIOR) and the percentage of wear of the detector tags (PATCH) were recorded three times a day, for 30 minutes each, during a week. Simultaneously, the activity of the animals was monitored through necklaces that measure activity and rumination (COLLAR). A blood sample was taken from each animal on the day of the heat, and 10 days after, for the determination of serum progesterone concentration (gold standard). Sensitivity, specificity, accuracy, positive predictive value and probability of false positives of the three tools (BEHAVIOR, PATCH and COLLAR) were calculated. The three heat detection methods showed similar sensitivity (BEHAVIOR = 96.6%, COLLAR = 100%, PATCH = 83.3%) with respect to the gold standard, but the probability of false positives was greater for behavioral observation and neck collar than patch (BEHAVIOR = 12.1%, COLLAR = 12.5%, PATCH = 3.85%). The three tools were efficient in detecting heifers in heat.