Abstract
BACKGROUND: Postpartum endometritis can cause subfertility in cows and reduce the reproductive performance of dairy herds. Thus, there is a critical need to improve the accuracy of the diagnosis of this disease, particularly in dairy cows. OBJECTIVES: This study confirmed the effects of the combined use of two non-laboratory methods: Metricheck device (MT) and ultrasonography (UT) to detect signs of endometritis and therefore predict the likelihood of pregnancy. METHODS: The reproductive tract of 67 lactating Holstein cows (25 primiparous and 42 multiparous) was observed at 4 and 6 weeks postpartum using the MT and UT. The cows with flecks and more purulent material in the vaginal discharge were defined as MT-positive, and the cows with uterine echogenic contents were defined as UT-positive. The combined definition was also used; both the UT and MT results or either the UT or MT result had to be positive for the final decision to be positive. The true-negative cows were determined as both MT-UT-negative. RESULTS AND DISCUSSION: When comparing the diagnostic results obtained by MT and UT, 37.3% and 32.8% of the total cows showed conflicting results at 4 and 6 weeks postpartum. The proportion of non-pregnant cows until 200 days postpartum was significantly greater in both MT-UT-positive cows than in the true negative cows. The hazard ratios of pregnancy rate were 0.37 for both MT-UT-positives relative to the true negatives at 4 weeks postpartum. Similar significant differences were not detected using the MT or UT alone. These results indicate that a more severe effect on the chance of pregnancy could be detected in cows that are both MT-UT-positive compared with those positive for MT or UT alone. CONCLUSIONS: The combined use of MT and UT could support veterinary practitioners in diagnosing endometritis, potentially improving the accuracy of predicting subsequent reproductive performance.