Ovarian response to P4-PGF-FSH Treatment in Suffolk sheep and P4-PGF-PMSG Synchronization in Cross-bred Ewes, for IVD and ET Protocol

Abstract

Abstract BackgroundThe success of an embryo transfer protocol in sheep depends on many factors, but the choice of drugs for the desired superovulation as well as the conception rate are most essential. Reproductive activity in sheep is characterized by a seasonality influenced by several factors such as photoperiod, latitude, temperature, nutrition and breed. Reproductive seasonality and nutritional condition are the main factors that influence embryo production in sheep. In sheep, some anatomical peculiarities limit the application of traditional reproductive biotechnologies used in cattle. MethodsIn vivo embryo production is often referred to as “multiple ovulation and embryo transfer” and involves ovarian superstimulation of the donor female, insemination or mating, uterine flushing for embryo recovery, and either cryopreservation or transfer of collected embryos to recipients. A total number of 60 sheep and 3 rams were included in this study, divided into 2 groups (receptors/donors). Donor Suffolk sheep were treated for superovulation using the P4‐PGF‐FSH protocol while the cross-bred recipients’ group was synchronized with P4-PGF-PMSG. ResultsOn the first day after superovulation, all ovaries had more than 5 dominant follicles, while corpora lutea were later observed in 83.3% sheep. The recovery rate was 83.3% while 72,9% embryos were transferable. Embryos were transferred directly into recipients. Fertility after 30 days was 68.57%, lambing rate was 91.6%, and CR 62.85%. This study showed that veterinary drugs (P4, FSH, LH, PMSG, PGF) used for superovulation were capable to induce estrus and synchronize ovulation in sheep, are topical and in increasing use worldwide. ConclusionsThe aim of this study was to conclude on the effectiveness of a wider on farm in vivo embryo transfer development program in Suffolk sheep, using several veterinary hormones. The application of a multiple ovulation embryo transfer (MOET) protocol has a positive effect in the production of in vivo derived embryos in Suffolk sheep and can guarantee the success of embryo transfer activity to ewes with lower genetic merit. Our research aimed at representing a model for sheep farms for a rapid improvement of productive traits.