Effect of long-term and short-term progestagen treatments on the induction of estrus and lambing rate in acyclic ewes [electronic resource].
تأثير المعاملة بالبروجستاجين لمدة طويلة و لمدة قصيرة على استحداث الشياع و معدل الولادة في النعاج الخاملة جنسيا.
- p.375-384.
Includes reference.
A total of twenty nine Romanov crossbred ewes were divided into three groups. Ewes in group 1 (n = 10) and group 2 (n = 9) long-term treatment received intravaginal fluorogestone acetate (FGA, 30 mg) for 14 and 12 days, respectively, with or without 500 ill PMSG injected at sponge removal. Ewes in group 3 (n = 10) short-term treatment received flourogestone acetate for 6 days plus i.m. injection of 500 ill PMSG at sponge withdrawal. All ewes were intramuscularly injected with 125 p.g PGF2Cl at sponge withdrawal. Percentage of ewes in estrus was significantly (P < 0.05) higher in long-term plus PMSG and short-term treated ewes than with long¬ term without PMSG (90 and 80% vs. 44.4%, respectively). The time elapsed from sponge withdrawal to onset of estrus was significantly (P < 0.05) longer in long-term treated ewes without PMSG than in both long-term ewes plus PMSG and short term treatment (48 h vs. 29 and 26 h, respectively). Lambing rate was higher in short-term and long-term treated ewes plus PMSG than in long-term treated ewes without PMSG (100 and 66.7% vs. 50%, respectively). However, within treatments number of lambs born, incidence of twins and fecundity rates were higher in ewes administered 500 ill PMSG than those not injected with PMSG. We concluded that short-term progestagen (6 d) combined with PMSG can be used successfully to induce fertile estruse late seasonal anestrus ewes.