Effect of ovsynch estrus synchronization protocol on fertility in crossbred ewes

The present study was designed to test the comparative efficacy of Ovsynch estrus synchronization protocols during two different phases’s i.e. breeding and out-of-breeding season in crossbred ewes. During both phases a total of 60 ewes were randomly divided into four groups (n=15 in each group) viz. Group I (Control out-of-breeding season), II (Treatment out-of-breeding season), III (Control breeding season) and IV (Treatment breeding season). The Ovsynch protocol (Group II and IV) consisted of buserelin acetate on day 0, cloprostenol sodium on day 5 and buserelin acetate on day 7 intramuscular (im). Blood sampling was carried out for estimation of plasma progesterone concentration in due course of study. Trans-rectal real-time B-mode ultrasonography (USG) was done for early pregnancy diagnosis at day 25 post-mating with reconfirmation on day 45. The results of the present study showed that the Ovsynch protocol was almost equally effective in induction of estrus resulting in better pregnancy rate and subsequent fertility during both seasons. The progesterone concentration did not vary significantly among all groups (P<0.05) on day 14, 25 and 45 post-mating. Thus, the Ovsynch protocol could be advised for improvement of reproductive efficiency during breeding as well as out-of-breeding season in crossbred ewes throughout the year.

HIGHLIGHTS

• Ovsynch protocol is equally effective for estrus induction in breeding and out-of-breeding season in ewes.

• Ovsynch protocol could improve reproductive efficiency in out-of-breeding season in ewes.