Effect of time of artificial insemination on fertility of progestagen and PMSG treated indigenous Greek ewes, during non-breeding season

A total of 2567 indigenous Greek ewes (Chios, Vlachiki and Vlachiki x Chios breeds) were used to determine the optimum time for insemination, followin g, synchronization of oestrus with MAP-impregnated intravaginal sponges and PMSG during non-breeding season. Within each breed group, the ewes were di vided into three subgroups and submitted to a double blind cervical artific ial insemination 48 and 60 h (subgroup I), 60 and 72 h (subgroup II) and 48 and 72 h (subgroup III) after sponge withdrawal. From the results of the p resent investigation it can be concluded that the conception rate in the Ch ios island breed is better than that in the Vlachiki x Chios breed, with th e latter being better than that in the Vlachiki breed. Using fixed time for Al, a better conception rate is obtained when applied 48 and 72 h after sp onge withdrawal for Chios and Chios x Vlachiki breeds, while for Vlachiki b reed a better conception rate is obtained when fixed Al is applied 48 and 6 0 h after sponge withdrawal. (C) 2001 Elsevier Science B.V. All rights rese rved.