Association among endometrial hyperemia, uterine bacterial infection, and characteristics of large ovarian follicles in dairy cows.

We investigated the association among endometrial hyperemia, uterine bacterial infection, and features of the large ovarian follicles in dairy cows. Genital organs were collected in a complete set at a slaughterhouse, and the degree of endometrial hyperemia was examined for the direct evaluation of uterine inflammation. The rate of bacterial infection in the uterus was higher in cows with endometrial hyperemia regardless of the severity of hyperemia, compared with cows without hyperemia. Moreover, the characteristics of the follicular fluid were changed in cows with uterine bacterial infection and included high concentrations of lipopolysaccharide and malondialdehyde (lipid peroxidation marker). These findings can be utilized as the basic information for the direct evaluation of the uterine inflammatory status in dairy cows.