Cushioned centrifugation during sperm selection increases the fertilization and cleavage rates of cattle embryos produced in vitro.

This study was conducted to evaluate the effect of utilization of an iodixanol-based solution as a cushioning method during the sperm selection utilizing discontinuous Percoll gradient centrifugation in in vitro production (IVP) of cattle embryos. In Experiment I, all aliquots of thawed semen were subjected to sperm selection using the same discontinuous Percoll® gradients, except for the following four conditions: presence of cushioning solution (Cushion Fluid, Minitube) during the first centrifugation process (C1), presence of cushioning solution during the second centrifugation process (C2), inclusion of cushioning solution in both centrifugation steps (C1-2), and no addiction of cushioning solution (C; control group). Recovery rates, sperm kinetics, and reactive oxygen species (ROS) production were evaluated. In Experiment II, sperm cells were processed using sperm selection conditions C and C1, and fertilization rates and embryonic development kinetics were compared between experimental groups. With use of condition C1, there was improvement in fertilization and cleavage rates when compared to use of condition C (56.4% compared with 45.5% and 80.0% compared 64.7%, respectively). In conclusion, results indicate the use of a cushioning solution during sperm selection positively affects the developmental potential of embryos.