In Vitro Culture and Evaluation of Embryos for Production of High Quality Bovine Embryos

Abstract

Recent advances in technologies associated with assisted reproduction in domestic animals have been remarkable. In cattle, immature oocytes can be developed to the blastocyst stage by in vitro-production (IVP) techniques in various formulations of media and different culture conditions [1–5], but many technical problems still remain. For example, the cryotolerance and rates of pregnancy of embryos produced by IVP techniques were not high [6, 7]. Comparative studies demonstrated that the quality of bovine embryos produced by IVP systems was lower than that of in vivo-derived embryos [8, 9]. Embryo quality is an important determinant of the success of practical embryo transfer. Accurate evaluation of embryo quality prior to the embryo transfer contributes to improvement in rates of p r e g n a n c y . T h e r e f o r e , s u c c e s s f u l a s s i s t e d reproduction in animals requires culture techniques for production of high quality embryos and an accurate method for assessment of embryo quality. This review introduces in vitro culture systems for production of high quality bovine embryos and a novel method, with scanning electrochemical microscopy, to assess the embryo quality.