Oestrus Synchronization in Merino Sheep Using Intravaginal Sponges, Estrumate and PMSG on Oestrus Activity during non-breeding season

Abstract

The aim of this study was to compare the effectiveness of different synchronization protocols on estrus activity in Merino ewes during the non-breeding season. The objectives of this study were (i) to determine the effectiveness of using intravaginal sponges alone to synchronize estrus during non-breeding season, (ii) to determine the effectiveness of using Estrumate alone to synchronize oestrus during non-breeding season, (iii) to determine the effectiveness of using the combination of intravaginal sponges, Estrumate and GnRH to synchronize estrus during non-breeding season. Four different protocols were used as follows: TRT A (control), TRT B (were inserted intravaginal sponge for 12 days), TRT C (double injection of prostaglandin at day 0 and 11), TRT D (intravaginal sponges 12 days, single injection of prostaglandin at day 12 and single injection of gonadotropin-releasing hormone). The results were statistically significant (p < 0.05) based on an interval from withdrawal of treatments to onset of estrus, estrus response, duration of estrus as well as interval from withdrawal of treatment to end of estrus during the non-breeding season hence ewes treated with double injection of prostaglandin was the most effective.