Change of culture medium positively influences the development and quality of in vitro cattle embryos

Although the practice of producing in vitro embryos (IVP) has become routine in the world, the quality of IVP embryos is still lower than that of in vivo embryos, and the conditions for obtaining in vitro embryos still need to be specified. This original research article presents data on the development and quality parameters of IVP embryos in cattle ( Bos taurus ), depending on the volume of in vitro culture medium (IVC) and its refreshment protocols. Post mortem bovine oocytes were cultured in a maturation medium, fertilized in vitro with frozen-thawed sperm, and transferred to 500 or 100 µl of BO-IVC medium (IVF Bioscience, UK) for embryonic development. The effects of not refreshing the IVC medium during the 8-day embryonic development period (NMR), half-refreshed medium (HRM) and completely refreshed medium (CRM) were compared. For HRM or CRM, after 3 days of culture, half of the initial 500/100 µl volume was replaced with fresh medium or embryos were transferred to 500/100 µl fresh medium. On day 8 of NMR, HRM, and CRM culture, the number of embryos developed to the blastocyst stage (BL) was evaluated, and the BL quality was assessed as per the total number of nuclei and the apoptotic nuclei counted cytologically. The 8-day-old blastocysts were also cultured for 2 days to the stage of hatched BL (HBL). CRM has been shown to improve embryo production regardless of the volume of the IVC medium when compared to NMR culture. Blastocyst formation increased from 23.0±1.5 and 25.8±0.8 % for 500 µl and 100 µl, respectively, to 45.7±4.8 and 52.1±4.9 % (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }