Effect of recovery method and oxygen tension on development of bovine oocytes fertilized and cultured in vitro

The aim of this study was to evaluate the effect of the recovery method and oxygen tension on in vitro embryo (IVP) production. In Experiment 1 the effect of two recovery methods, aspiration and dissection on embryo division and development rates was evaluated. The 72 hour post-insemination division rate was 71.4% with aspiration and 61.0% with dissection (p<00.5), while no statistical difference was found on blastocyst rates 7 and 9 days post-insemination. In Experiment 2 two oxygen tensions, 5 and 20%, were compared in the culture stage obtaining higher division rate and 7-day blastocyst rate with 5% oxygen tension (69.7 and 29.8% respectively) compared with 20% oxygen tension (59.7 and 19.3% respectively). The results suggest that the aspiration recovery method and 5% oxygen tension must be considered to achieve optimal conditions for in vitro embryo production.