Setting up an efficient individual ovine embryo culture system in comparison with conventional method

The development of an ovine in vitro embryo production system where individual embryos could be followed through to the blastocyst stage would be of interest to several fields of study and would allow us to characterize developmentally competent embryos through non-invasive analysis of the metabolite constituents of their corresponding culture media. The present study was designed to establish an individual ovine embryo culture system, with embryo development rates similar to that observed under grouped culture conditions. After IVM and IVF, presumptive zygotes were cultured in groups or individually, either in 20 and 10 microliter drops. Cleavage and blastocyst rates at days 3, 6 and 7 were evaluated. Moreover, the effect of 5 or 10 percent fetal calf serum added to individual culture at day 3, were evaluated. No refreshing was made. Cleavage rate, total blastocyst, early, expanded and hatched blastocyst were similar for all treatments at day 6. Total blastocyst rates at day 7 was lower in group culture than that of individually cultured and in another experiment, total blastocyst and early blastocyst rate was different at day 7 post-cultured. The results of this study show clearly that a large proportion of ovine zygotes can develop to the blastocyst stage when cultured individually, adding 10 percent fetal calf serum at day 3 and without refreshing.