Effect of the dose of equine chorionic gonadotrophin [ECG] on ovarian response and embryo recovery in Egyptian baladi goats

ABSTRACT

The effects of doses of equine chorionic gonadotrophin [eCG] for a simple superovulation method in does [Goats] were investigated on ovulation rate, proportions of fertilized oocytes and normal embryos at recovery. The does were treated with intravaginal sponges impregnated with medroxy progesterone acetate [MAP] for 12 days. For superovulation, an intramuscular injection of eCG was given at 24 h before sponge removal. Does were divided into nine equal groups [n = 5] A, B, C, D, E, F, G, H and I. Each received 100, 200, 300, 400, 500, 600, 700, 800 and 900 IU of eCG respectively. All does were naturally inseminated by four healthy fertile bucks. Laparotomy and embryo recovery were done for does on day six. The mean numbers of corpora lutea of nine groups were [2.8 +/- 4.34, 4.4 +/- 0.55, 2.8 +/- 1.10, 4.2 +/- 1.79, 6.8 +/- 2.39, 9.6 +/- 4.45, 6.8 +/- 5.81, 6.6 +/- 3.05 and 5.8 +/- 5.17] respectively. While mean of unovulated follicles were counted after laparotomy for nine groups respectively [3.4 +/- 1.14, 5.8 +/- 1.30, 7.0 +/- 2.35, 5.6 +/- 1.82, 6.8 +/- 2.05, 7.2 +/- 1.92, 9.8 +/- 4.71, 11.2 +/- 5.02 and 10.6 +/- 3.58]. On the other hand the percentage of normal embryos were 0, 15.0, 42.86, 42.11, 54.84, 66.67, 48.64, 38.0 and 45.24] of normal embryos. The present study indicates that an appropriate eCG dose would be 600-700 IU for a simple superovulation method in does pre-treated with Progestagen-impregnated vaginal sponges