Ovarian response, embryo recovery and progesterone profile in goats following human chorionic gonadotrophin administration on day 7 of oestrous cycle prior to superovulatory treatment*

Abstract

The effect of human chorionic gonadotrophin (hCG) on clay 7 of oestrous cycle, prior to start or superovulatory treatment, on ovarian response, embryo recovery ancl progesterone profile was studied. Cyclic non-descript goats (16) were randomly allocated to control (n=8) and treatment (n=8) groups. Goats in control group received 20 NIH-FSI-SI units in 8 divided doses (4/4, 3/3, 2/2, and 1/1 units) over 4 days (day 10 to days 13 of the oestrous cycle) and 10 mg dinoprost tromethamine on day 12 at the time of fifth FSH injection. The goats of treatment group in addition received 500 IU hCG on day 7 of estrous cycle. All goats in both groups were injected 500 IU hCG, 10-16 hr after onset of superovulatory oestrus and covered by natural service 12 hr interval till the end of the oestrus. Laparotomy was performed on day 6 for assessment of ovarian response and embryo recovery. Blood samples were taken at different intervals for progesterone determination. The mean number of corpora lutea were lower (3.12±1.05 vs 5.12±0.93), number of unovulated large follicles were higher (3.12± 1.20 vs 2.00±0.90) and number of white vascular corpora lutea were lower (1.00±0.75 vs 1.50± 1.50) in treatment group than that of control group. However, the differences were nonsignificant. The mean number of embryo recovered were similar (2.87±0.76 vs 2.87±0.51) in both groups. The progesterone levels were higher in hCG treated group than that in the control group on the corresponding days. It was concluded that there is no significant effect of hCG injection given prior to superovulatory treatment on ovarian response embryo recovery and progesterone levels.