Improving the development of bovine in vitro produced embryos cultured individually

Abstract

Previous research in bovine embryology has found that embryos cultured individually have limited ability to develop compared to their counterparts cultured in a group of other embryos. This investigation aimed to find if any of three different interventions over two experiments would increase development of individually cultured embryos to that of group cultured embryos. In the first experiment both the addition of serum/serum replacer and a co-culture with bovine granulosa cells were applied to individually cultured embryos in a 3x2 design. None of the interventions was found to be significantly different from the others, and all resulted in significantly lower development than embryos cultured as a group (avg. 4.7 +/- 1.93% individual vs. 21.7 +/- 3.76% group). However, a significant difference was found in the hatching rate between blastocysts cultured in media including cells (71.4 +/- 17.07%) and those cultured without cells (18.1 +/- 11.63%). In the second experiment, embryos were either cultured in standard droplets or microwells made at the bottom of culture droplets either in groups or individually for a 2x2 design. This experiment experienced poor development in all treatments including the group control, and none of the treatments were found to be significantly different from each other. However, the hatching rate of blastocysts cultured in multiple microwells was significantly higher than those cultured individually in droplets. To summarize, none of the treatments increased the development rate, but embryos cultured with granulosa cell co-cultures and in group microwells showed improvements in hatching rates.