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, following, synchronization of oestrus with MAP-impregnated intravaginal sponges and PMSG during non-breeding season. Within each breed group, the ewes were divided into three subgroups and submitted to a double blind cervical artificial 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 present investigation it can be concluded that the conception rate in the Chios island breed is better than that in the Vlachiki x Chios breed, with the 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 sponge withdrawal for Chios and Chios x Vlachiki breeds, while for Vlachiki breed a better conception rate is obtained when fixed Al is applied 48 and 60 h after sponge withdrawal. (C) 2001 Elsevier Science B.V. All rights reserved.