EN
The aims of this study were to compare two methods of estrus synchronization and to evaluate the effectiveness of the PMSG treatment combined with P4 application. Fifty non-lactating seasonal anestrus fat-tailed ewes were randomly assigned into five groups. The controlled internal drug release devices (CIDR) were applied during day 14 in group I and in group II. Progesterone impregnated sponges were applied during day 14 in group III and in group IV. And then 500 IU PMSG was injected in group I and III i.m. intravaginal devices removed. Ewes in group V served as controls. There was no difference between the groups in the peak value of LH and LH surge. Although LH surge was seen in the control groups 5 sheep, none of the control ewes expressed estrus. Different progestagen treatments have no different results when they are evaluated in terms of the success of the estrus synchronization. PMSG application, after P4 treatment, increased the success of the synchronization.