Subclinical endometritis in beef cattle in early and late postpartum: Cytology, bacteriology, haptoglobin and test strip efficiency to evaluate the evolution of the disease.

In cows, detrimental effects on fertility are mainly caused by clinical and subclinical endometritis (SEM). As demonstrated in previous work, Piedmontese cattle are affected by a higher rate of infertility and presence of SEM. The objective of this study is to assess the pattern of SEM at 30 and 60 days postpartum by evaluating the correlation between uterine cytology and microbiology, analyzing SEM consequences on reproductive career and verifying the reliability of rising inflammatory proteins - haptoglobin and the test strip test. Seventy healthy cows were enrolled and sampled at 30 and 60 days postpartum; cytology and bacteriology as well as haptoglobin and test strip were evaluated. The ROC curve for cytology set the optimal cut-off at 6.5% at 30 days and 2.5% at 60 days for a Partum-to-Conception (PC) interval of 120 days. The cytological positivity was negatively correlated with fertility, at 30 days, but not at 60 days. A positive bacteriological test was not correlated with an increase in the PC at either 30 or 60 days postpartum. The presence of a calving parlor affect the fertility (P < 0.05) but not the presence of parity or suckling calf and parity. The ROC curve for strip test protein at 30 days postpartum set a cut-off of 2% for PC. No difference in serum haptoglobin was observed between negative or positive cytology/bacteriology in postpartum cattle. The test strip results for proteins have demonstrated a utility at 30 days postpartum for screening the cows that are at risk of developing an increased PC > 120 days.