Impacts of GnRH, PMSG and HCG Treatments on Follicular Diameter, Conception and Lambing Rates of Egyptian Ewe Lambs Using Intravaginal Sponges

Abstract

ABSTRACTThe influence of gonadotropin releasing hormone (GnRH), Pregnant Mare SerumGonadotropin (PMSG) and human Chronic Gonadotropin (hCG) on some reproductive responses ofEgyptian ewe lambs was evaluated. Twenty five animals (aged 8 – 12 months and weighed 27 - 33Kg) were divided into 5 groups ( 5 ewe lambs each). Group (1) served as a control, Group (2),received vaginal sponges impregnated with MAP (60 mg medroxy progesterone acetate) for 14 days,during this period, animals fed 3 kg Berseem, (Trifolium alexandrinum) plus 500 gm concentrate /head/ day. Group (3), received vaginal sponges impregnated with (60 mg, MAP) for 14 days, on theday of sponge removal; each animal injected by PMSG (250 IU, I/M). Group (4) animals received1.25 ml Receptal (0.5 μg, GnRH) I/M, on day 0, seven days later, ewe lambs injected with 0.5 mlEstromate (125 μg. PGF2α) I/M, after 48 hours, animals treated with a second dose of GnRH. Group(5) received two injections of (0.5 ml Estromate) at days 0 and 7, respectively, after 72 hours from thesecond dose of PGF2α ewe lambs were injected 0.2 ml hCG. Heat detection was performed and transrectalultrasound scanning also performed to confirm estrus, pregnancy and follicular diameter. Theresults revealed that, administration of PMSG (group 3) reduced the interval to estrus (the onset ofheat /hours) significantly (P< 0.01) compared with control and other groups. Regarding conceptionand lambing rates, groups 2, 3, & 4 had affected significantly (P˂ 0.01) compared to groups 1 & 5.Follicular diameter (mm) tended to increase significantly in treated groups than the control one.Results suggest that, tested hormones have effect on selected reproductive responses of Egyptian ewelambs while administration of PMSG (Group 3) has the best response compared to other hormonaltreatments.