Fatemeh khalilavi
Morteza mamoei - Department of Animal Science, Faculty of Animal and Food Science, Ramin Agricultural and Natural Resources University, Mollasani, Ahvaz, Iran
Salleh tabatabaei - Department of Animal Science, Faculty of Animal and Food Science, Ramin Agricultural and Natural Resources University, Mollasani, Ahvaz, Iran
Morteza chaji - Department of Animal Science, Faculty of Animal and Food Science, Ramin Agricultural and Natural Resources University, Mollasani, Ahvaz, Iran

An oestrous synchronization study was conducted on 24 ewes, during the anoestrus season. one dose of eCG administration 300 IU eCG (n = 12) and one doses of 500 mg royal jelly in combination with 300 IU eCG (RJ-eCG, n = 12) were compared regarding synchronization efficiency (oestrous response and time to onset of oestrus) and fertility (pregnancy rate, lambing rate and Multiple birth rate). Behavioral estrus was checked using fertile rams at 6 h intervals for 5 days beginning on d 1. Non-return rates were monitored from 15 day after sponge removal to 20 day with the aid of teaser rams. There were no significant differences in terms of oestrous response due to differences in the dose of eCG and RJ-eCG administration. However, intervals to onset of estrus were shorter (P< 0.05) in RJ-eCG treated (37.16 h) than 300 IU eCG (45.175 h) ewes. First-cycle pregnancy was greater (P< 0.05) in RJ-eCG treated (81.81) than 300 IU eCG (50%) ewes, respectively. Other indicators studied were not different in the groups received 300 IU eCG and RJ-eCG. Results demonstrate that The treatments of RJ- eCG in conjunction with sponge-MAP were more effective in induction of estrus and improvement of fertility

Ewes; Fertility; Progestagen; RJ-eCG; Anoestrus season