Effects of GnRH or HCG on Ovarian Response in PMSG-Superovulated Ouled Djellal Ewes (Algeria)

摘要

Superovulation plays an important role in the embryo transfer (ET) programs. The objective of thisstudy was to evaluate the effects of Gonadotropin-releasing hormone (GnRH) or human chorionicgonadotropin (hCG) treatment on ovarian response in PMSG-superovulated ewes. Intravaginal pessariescontaining 40 mg fluorogestone acetate (FGA) were inserted in all ewes (n=14) and remained in situ for 14 days.Two days prior to pessary removal, all ewes were treated with 1000 IU of PMSG. On the day of sponge removal(day 0), the females were randomly assigned to 3 treatments. The first group (T1; n=3) received no furthertreatment, while second group (T2; n=5) treated inter-muscular with GnRH (100 ug) at day 1, finally the thirdgroup (T3; n=6) treated inter-muscular with hCG (500 IU) during days 0-2. On day 8, laparotomy was performedto assess numbers of corpora lutea (CL) and anovulatory follicles (AF). Blood samples were collected foranalysis of serum progesterone (P4) using radioimmunoassay (RIA) method. The results obtained for first,second and third group were in number of CL (6.33±1.15, 9.00± 1.58 and 10.50± 5.54), number of AF (2.00 ± 3.46,3.60 ± 6.50 and 4.16 ± 5.70), then the levels of P4 (5.75 ± 4.45, 13.97 ± 4.67 and 13.22 ± 6.80 ng/ml), respectively.In conclusion GnRH or hCG treatment post sponge removal increases number of CL and improves lutealfunction after PMSG-superovulatory treatment. However, it didn’t reduce the number of AF.