331 EFFECT OF SUCESSIVE LAPAROSCOPIC OOCYTE RECOVERY AFTER HORMONAL TREATMENT IN CROSSBRED GOATS

Abstract

Laparoscopic oocyte recovery (LOR) is a valuable tool for obtaining oocytes for in vitro embryo production. When preceded by a treatment of ovarian stimulation, this technique produces an increase in the amount of oocytes recovered. However, a little information has been found to respect the effect of successive hormonal treatments on both oocyte quantity and quality. Therefore, the objectives of this study were to evaluate the ovarian response and quantitative and qualitative COC production. Five adult crossbred goats were hormonally treated with intravaginal sponges containing 60 mg of medroxyprogesterone acetate (MAP, Progespon, Syntex, Buenos Aires, Argentina) for 11 days. In the 8th day of progestagen treatment, 50 μg of prostaglandin F2α analogue (Ciosin, Coopers, São Paulo, Brazil) was administered by i.m. injection. At this time, ovarian stimulation was initiated by the administration of 120 mg pFSH (Folltropin-V, Vetrepharm, Canada) distributed in five decreasing doses (30/30, 20/20, 20 mg), at 12-h intervals. The animals were fasted for 24 h before the laparoscopic procedure, which was performed just after the sponge removal. A laparoscopic system connected to a 22-gauge needle (WTA, Watanabe, Brazil) and a vacuum pump (Biovacuum, Biocom, Brazil) providing 30 mm Hg was used. All follicles with a size larger than 2 mm present in both ovaries were counted and aspirated. The collection medium was TCM-199 supplemented with HEPES (10 mM), heparin (20 IU mL^-1), and gentamicin (40 μg mL^-1). The COCs were graded based on presence of cumulus cells and cytoplasm homogeneity (I to IV). The hormonal treatment and LOR procedures were repeated three times at 14-day intervals. Data were expressed in percentage or mean ± SEM. The differences were analyzed using ANOVA and Tukey’s or Fischer’s exact test when appropriate, with P < 0.05. No statistical differences were found (P > 0.05) for the number of follicles obtained in each LOR session: 17.0 ± 3.91, 18.75 ± 2.59, and 18.0 ± 4.73, respectively. Repeated LOR procedures also did not affect (P > 0.05) the number of aspirated follicle (15.0 ± 3.92, 15.5 ± 2.33, and 16.0 ± 4.36), resulting from the three sessions, respectively. Average recovery rates were not statistically different (P > 0.05), resulting in 74.7%, 62.9%, and 64.6% between sessions. With respect to the percentage of viable COCs (GI and GII) were not observed statistical differences (P > 0.05), as verified the follow values at 1st to 3rd sessions: 76.79%, 84.62%, and 74.19%. In conclusion, three successive hormonal stimulation LOR procedures did not cause detrimental effects on quantitative and qualitative oocyte production, suggesting that this protocol can be used for programs of in vitro goat embryo production.

This study was supported the following Brazilian agencies: FINEP, CNPq, FUNCAP, and CAPES.