Rectal Temperature, Calving-Related Factors, and the Incidence of Puerperal Metritis in Postpartum Dairy Cows

Abstract The objectives of this study were as follows: 1) to evaluate the association among abnormal calving, parity, and season on the incidence of puerperal metritis (PM) and clinical endometritis (CE) during d 3 to 13 and 20 to 30 postpartum, respectively; 2) to describe the rectal temperature (RT) of cows with PM before diagnosis; and 3) to document associations among PM, CE, and reproductive performance in lactating dairy cows. This study followed a prospective observational study design. Cows were classified as having an abnormal calving status (AC), i.e., cows calving with dystocia, twins, retained fetal membranes, or some combination of these conditions, and having a normal calving status (NC). Daily RT was recorded from d 3 to 13 postpartum for all cows, and health examinations were performed on cows that appeared not well. A total of 450 calvings were evaluated. Cows with an AC had greater odds of PM than cows with NC [adjusted odds ratio (AOR) = 4.8; 95% confidence interval (CI) = 2.9 to 8.0). A season by parity interaction showed that primiparous cows that calved during the warm season had lower AOR of PM than during the cool season (0.24; 95% CI=0.09 to 0.62), whereas multiparous cows did not have seasonal effects on PM (1.43; 95% CI=0.65 to 3.18). Cows with AC have greater AOR for CE than cows with NC (2.8; 95% CI=1.7 to 4.9), and greater AOR of CE were detected in cows diagnosed with PM than in cows without PM (2.2; 95% CI=1.1 to 3.9). Rectal temperature in cows with PM increased significantly 24h before diagnosis of PM, reaching 39.2±0.05°C on the day of diagnosis. In cows with PM and fever at diagnosis, the RT began to increase from 72 to 48h before the diagnosis of PM and continued to increase to 39.7±0.09°C on d 0 (day of diagnosis). Nonetheless, cows with PM without fever at diagnosis had no daily increases in RT before diagnosis of PM. Still, the RT on d 0 was different from cows without PM. Cows without PM had a stable RT (38.6±0.01°C). There were no detected differences in first-service conception risk or cumulative pregnancy risk by 150 d postpartum between cows with or without PM. Still, a season effect on first-service conception AOR (warm vs. cool=0.98; 95% CI=0.18 to 0.72) and accumulated pregnancy AOR by 150 d postpartum was detected (warm vs. cool=0.18; 95% CI=0.10 to 0.33).