Efficacy of the application of estrus synchronization in sheep during non-breeding season

Galina Mircheva, Radka Malinova and Zornica Petkova

Abstract: The present study examines the success rate of the estrus synchronization in 289 sheep depending on their age group. All animals were subject to the same synchronization scheme. It involved the insertion of vaginal progesterone-containing sponges for sheep impregnated with fluorogestone acetate (FGA) 30 mg which remained in the vagina for 14 days. Lyophilized serum gonadotropin hormone (PMSG) 500 IU/ewe was applied after the sponge removal. The first artificial insemination was performed 48 hours later, and the second one – after around 5 hours. The average pregnancy rate for all groups was 61.6% ± 3.486 (p < 0.001). Upon examining the percentage of pregnant ewes depending on the age group, we ascertained that the second age group comprising the ewes from 2 to 4 years had the best pregnancy rate – 72.9%. Predictably, the lowest pregnancy rate- 42.6% was that in the first age group comprising the one-year-old animals. The third age group comprised all animals above 5 years. Its pregnancy rate was 54.9% at p < 0.001. Significant differences were reported with reference to group one and two at p < 0.001 and group two and three – p < 0.05. The differences between age group one and three were insignificant p = 0.238.

Keywords: estrus synchronization; ewes; FGA sponges; sheep

Date published: 2022-11-01