Implementation of the in vitro embryo production technique in sheep in Costa Rica

Abstract

In this study, the ovine embryo production technique with in vitro fertilization was implemented in the Animal Reproduction Department of the Veterinary Medicine School, Universidad Nacional, Costa Rica (UNA). A total of 63 ovaries were collected from slaughterhouse’s ovaries, which were transported within 

one hour to the Veterinary Medicine school. The follicles were aspirated by using oocyte collection medium (OPU, Bioscience®), and oocytes surrounded by at least one complete layer of cumulus cells were selected (216/341), placed in maturation medium (IVM, Bioscience®) and incubated at 38.8°C during 22 to 24 h, in a humid atmosphere with 5% CO2. The 91.2% (197/216) of the matured oocytes that showed good cumulus expansion and homogeneous cytoplasm, were fertilized with 1-2 x10⁶/ml semen in fertilization media (IVF, Bioscience® during 16-22 h. The zygotes were denuded and transferred to culture medium (IVC Bioscience®) and a low oxygen atmosphere. After a 24 h culture, the cleavage rate was 57.36% (113/197). After 7 days of culture, the blastocysts rate was 20.81% (41/197) in relationship to the matured oocytes, and 36.28% (41/113) according to the cleaved zygotes.

Our results are a first step towards the application of sheep in vitro embryo production in Costa Rica. Its importance lies on its potential to promote genetic and productive enhancement in small ruminants but also contributes to educational and training purposes that bring new research opportunities aimed to solve local needs.