the histopathological survey of uterine tissue in holstein dairy cows with or without recorded reproductive disorders

the objective of the study was to evaluate the uterine histopathological changes in holstein dairy cows, within the range of 90-145 day in milk, with or without clinical history of reproduction system disorders. lactating holstein cows (n =133) with (n=92, 69.17%) or without (n= 41, 30.82%) recorded clinical signs of reproduction diseases were examined for uterine histopathological lesions. the cows in treatment group were inseminated artificially for 3 times after calving or did not have any recorded estrus signs. the cows in control group were not inseminated. biopsy of the endometrium and submucosa were obtained using a sterile alligator-jawed (rounded) biopsy forceps. the inseminated cows were at various stages of the estrus cycle. the results showed that 64.13% and 46.34% of cows with or without recorded clinical reproductive disorder had histopathological lesions, respectively. there were no significant differences in histopathological changes between cows with or without reproductive disorder history (p≥0.05). chronic endometritis was the most common microscopic lesion in cows with (34.61%) or without (17.94%) recorded reproductive disease. clinical endometritis was the most common reproductive disorder (20.65%). the rate of histopathological lesions in repeat breeder cows was16.3%. in conclusion, endometrial biopsy could be a useful diagnostic tool to evaluate future fertility of the dairy cows because, cows with or without reproductive disorders may show histopathological lesions.