Abstract: The response to superovulatory treatment and the embryo yield of Dorper ewes in a non-breeding season were evaluated. Average 65 kg, weight, 3 years old donor ewes were inserted CIDR for 12 days and divided into four superovulation treatment groups; Exp. I: 12 mL Folltropin+200 I.U. eCG (n = 25); Exp. II: 10 mL Folltropin+200 I.U. eCG (n = 20); Exp. III: 10 mL Folltropin+600 I.U. eCG (n = 25) and Exp. IV: 10 mL Folltropin+750 I.U. eCG (n = 10) with single shot of FSH at CIDR removal. Donors were superovulated using FSH-p (total of 20 mg) (Folltropin-V; Vetrepharm, Canada) applied in six decreasing doses of 3, 2.5, 2, 2, 1.5, 1 mL i.m. starting 60 h before CIDR withdrawal. Donors underwent intrauterine AI with fresh diluted semen (a minimum of 50x106 motile sperm/each uterine horn) 40 h after CIDR removal and embryos collected 6 days after insemination. The CL responses were found to be similar in all treatment groups (Exp. I: 11.7±1.18; II: 9.7±1.31; III: 8.4±1.76 and IV: 9.9±1.63). Superovulation response (CL>3) was found relatively but not significantly higher in lower dose of eCG treated Exp. I: 92% and II: 91%, respectively compared to III: 76% and IV: 75%. Transferable embryo numbers for a fresh MOET program were found slightly higher (P: 0.333) in donors in Exp. III with 7.8 ±1.2 than those recorded for donors in Exp. I (4.7±1.12), II (6.3±1.24) and IV (6.3±1.7). The significant difference (p<0.05) was observed in embryo recovery rates; Exp. II and III: 63%, Exp. I: 38% and IV: 43%. Stages of embryonic development were also affected by the different hormonal treatments used in the study Exp. I and IV giving the best results for a fresh MOET program. In conclusion, it was found that Dorper ewes treated with different superovulation protocols in out of season (May) in vivo fresh embryo MOET program yielded 9 embryos and the recovery rate was markedly higher than those of earlier findings. Study also showed that a single FSH injection can be used in place of decreasing dose of multiple FSH injections with similar results.
S. Ocak, E. Emsen and Sinan Ogun, 2013. Ovulation Rate and Embryo Yield of Dorper Sheep in Non-Breeding Season under Different Superovulatory Protocols. Journal of Animal and Veterinary Advances, 12: 726-730.