Reproductive performance of Ossimi sheep as affected by oxytocin injection during mating season.

Abstract

ABSTRACTTwenty adult Ossimi ewes were used to study the effect of premating oxytocin Intramuscularinjection (IM) on some reproductive traits. They divided randomly into equal two groups.Ewes in both groups were IM injected by 1ml GnRH (1st inj.) at day 0 (GnRH analogue contained0.004 mg Bussrelin (Receptal. Intrvet, International BV Boxmeer-Holland). Then at day 7, theyinjected (IM) by 0.7ml PGF2α analogue (Estrumate, Coopers Animal Health LTD, Berkhamsted-England). Each ml of Estrumate contained 250 μg Cloprostenol Acetate. Then, ewes injected thesecond GnRH dose (1 ml analogue) at day 9, two days post PGF2α injection. Oxytocin (20 I.U/IM ,Adwia Company) was only IM injected to each ewe in the first group immediately pre-mating, oneday after the second injection with GnRH. Another oxytocin injection was given 12 hr. post the firstinjection, after pre-second mating by the same rams. Ewes of the second group (control) were notinjected oxytocin premating by the same rams, one day after GnRH second injection.Results showed improvement in most reproductive traits of oxytocin injected ewes. Thepercentages of improvement were 33.33% for estrus rate, non-return rate and lambing, 25% fortwining rate, 8.67% for litter size and 44.44% for fecundity, compared to the control group. P4concentration was high (P<0.05) in treated group affected by oxytocin injection. Thereafter, P4decreased in all treated groups after PGF2α injection. Post-2nd GnRH injection, P4 levels showed apronounced increase in all treated groups. At day 20 post-mating, P4 levels showed the highest valuesin both groups. It could conclude that premating oxytocin Intra-muscular injection could use toimprove reproductive performance of Ossimi ewes.