Short- and Long-Term Storage of Non-Domesticated European Mouflon (<i>Ovis aries musimon</i>) Cumulus–Oocyte Complexes Recovered in Field Conditions

Abstract

Reproductive biotechnologies can be used as a supporting tool, through gamete conservation and in vitro embryo production, in the preservation of invaluable and irreplaceable animal genetic resources. In the present study, immature mouflon cumulus–oocyte complexes (COCs) collected from ovariectomized female ovaries underwent short- or long-term conservation (24 h maintained in Earle’s/Hank’s (EH) medium or vitrification) under field conditions and afterwards transported to the laboratory where they were cultured for in vitro maturation (IVM) and assessed for oocyte meiotic competence and bioenergetic–oxidative status. Utilization of both storage techniques led to COC morphology preservation, as well as cumulus expansion and oocyte meiotic resumption after the IVM procedure. Quantitative bioenergetic–oxidative parameters were reduced in vitrified oocytes compared with EH ones. Immature COC storage needs to be optimized in both domesticated and non-domesticated sheep as a part of the strategy to avoid the loss of valuable genotypes of these animal species.

Keywords

• female mouflon
• oocyte
• field oocyte collection
• EH holding
• vitrification
• in vitro maturation (IVM)