Temporal histologic evaluation of the endometrium of Nelore cows (Bos Taurus Indicus) in Southeast Brazil treated with Cloprostenol Sodium at the postpartum

Uterine histological analysis by serial biopsies are an important tool not only for a better understanding and evaluation of physiological events involved in the process of uterine involution, but also for the identification and monitoring of pathological process that may compromise reproductive life. This study describes a temporal histological changes in endometrial tissues from multiparous Nelore cows in Southeast Brazil treated or not treated with Cloprostenol sodium 1 and 4 days postpartum (DPP), to determine if the treatment promotes histological endometrial involution. Cloprostenol sodium was administered on 1 and 4 DPP and endometrial biopsies were collected 1, 7, 14, 28, and 42 DPP using a Yomann's biopsy instrument. The presence or absence of myometrial and endometrial tissue and its integrity, number of endometrial glands (classification 0 to 3), edema, hemorrhage, vascular congestion and type of epithelial cell was assessed. The average number of leukocytes was recorded. There was observed difference between groups on the number of endometrial glands (P <= 0.05) at one-time point. In addition, the degree of inflammation was reduced (P <= 0.05) on time points. Cloprostenol sodium did not alter the histological appearance of uterine tissue during the postpartum period or reduce the period of uterine involution. Additionally, serial biopsies did not affect the fertility of the animals.