OVARIAN HISTOLOGIC IN STIMULATING EWES SUBJECT TO SUCCESSIVE SESSIONS FOLLICLES ASPIRATION.

Abstract

The aim of the present study is to verify the occurrence of ovarian histological abnormalities caused by repeated follicular aspirations in ewes that underwent hormone stimuli. Eighteen Santa Inês ewes will be randomly selected and distributed into three groups (n=6) (G0, G1, G9), according with the number of aspiration sessions (0, 1, and 9 sessions, respectively). All animals will be oestrus-synchronized with 60 mg of medroxyprogesterone-acetate sponge (day 0), which will remain in place for 6 days. In day 5, animals will receive intramuscular 37.5 µg of d-cloprostenol and 300 IU of equine Chorionic Gonadotropin (eCG). Followed the oestrus synchronization, ewes will receive a single dose of 80 mg Follicle-stimulating hormone and 300IU of eCG, 36 hours after the procedure. Follicular aspirations (G1 and G9) will be a carried out by means of video laparoscopy, with an interval of 7 days among them. Retrieved oocytes from each group will be counted, evaluated, and morphologically classified; after they will undergo in vitro maturation for observation of nuclear and cytoplasmic stadium. In G9, comparative analysis will be accomplished between retrieved and matured oocytes. After the last intervention, the ovaries will be collected by laparotomy, grossly evaluated, submitted to histological processing. Histological sections will be evaluated by fields, and the intensity of the inflammatory reaction classified as absent (-), mild (+), moderate (++), and severe (+++). Data will be assessed by one way repeated measures ANOVA or by the Friedman´s test, followed by Tukey post hock test. Significance level will be set at P < 0.05.