Authors : I. Gharbi, M .Ferrouk , A. Dechicha , G. Baril , J.F. Beckers and D. Guetarni
Abstract: The objective of this study was to evaluate the effect of treatment with GnRH agonist (Buserelin) on ovarian follicular status, the response to super ovulation induction and in vivo embryo production in Ouled Djellal ewes breed. Twenty (n = 20) cycling ewes were allotted into two groups, the first (n = 10) received subcutaneously a daily injection of 40 μg buserelin for 14 days prior to superovulatory treatment (pretreated group) while the second group (n = 10) did not receive GnRH agonist before superovulatory treatment (control group). Before batching, the ovarian follicular population was assessed by laparoscopy numbering of the ovarian follicles. In the pretreated ewes a significant increase in small follicles (8.50±1.64 vs. 15.50±2.74, p<0.01) and a suppression of large follicles (≥4 mm) (4.3±0.76 vs. 0.0, p<0.001) was observed after treatment with Buserelin. In addition to the pretreated group, the number of small follicles prior to FSH treatment was higher and the number of large follicles smaller than the control group. The ovulatory response and the number of transferable embryos per ewe treated was significantly higher in ewes pretreated than in control ewes (ovulatory response: 17.8±1.56 vs. 9.1±1.11, p<0.001), (transferable embryos: 10.2±1.87 vs. 4.1±0.40, p≤0.01). Compared to the pretreated group a higher percentage of degenerated embryos was recorded in the control group (control: 20.40 vs. 7.27 pretreated, p<0.05). Improving of the embryos production in Ouled Djellal sheep can then be obtained by using a treatment with GnRH agonist and ovarian preparation for superovulation induction in allowing the terminal follicular growth inhibition and increasing of small follicles number at the start of FSH treatment.
I. Gharbi, M .Ferrouk , A. Dechicha , G. Baril , J.F. Beckers and D. Guetarni , 2012. Follicular Status and Embryo Production in Ouled Djellal (Algeria) Ewes Breed Pretreated with a GnRH Agonist. Journal of Animal and Veterinary Advances, 11: 791-798.