Evaluation of an accelerated lambing system in Syrian Awassi ewes, using hormonal treatments inside and outside the breeding season

An experiment was carried out on Syrian Awassi ewes to assess the accelerated lambing system (three lambings in 2 years) by synchronising and induction of oestrus and increasing ovulation rate using hormonal treatments (intravaginal sponges: FGA + equine chorionic gonadotrophin: eCG). Fifty intact cyclic Syrian Awassi ewes aged 2- 4 years with an average live weight of 51.4 kg were used for 4 years (6 lambings). Ewes were divided into 2 groups: 40 ewes in the treated (T) and 10 in the control (C). Ewes in the T group were treated with FGA for 14 days and injected intramuscularly at sponge withdrawal with 500 IU eCG. Results indicated that, throughout the 6 breeding periods, oestrus induction rate was 100%, and all ewes in the T group were mated within 1-5 days post sponge removal as compared to 10-11 days for ewes in the C group. Treated ewes had higher rates of lambing, multiple birth and fecundity. Repeated administration of eCG (6 times at 8 months interval) had no negative effect on fertility of Syrian Awassi ewes. However, anti-eCG antibodies were produced following eCG injections. (author)