Effect of magnetized extender on sperm membrane integrity and development of oocytes in vitro fertilized with liquid storage boar semen

The objective of this study was to evaluate the effect of a magnetized extender on sperm membrane damage and development of oocytes in vitro fertilized with liquid storage boar semen. Before semen dilution, extender was flowed through a neodymium magnet (0, 2000, 4000 and 6000 G) for 5 min and collected semen was preserved for 168 h at 18 °C. In results, plasma membrane integrity with live sperm was significantly higher in semen treated with extenders magnetized at 4000 G than sperm treated with extenders magnetized at 0 G during semen preservation for 120-168 h (p < 0.05). In addition, acrosomal membrane damage was significantly lower in semen treated with extenders magnetized at 4000 and 6000 G compared to 0 and 2000 G during semen preservation for 168 h (p < 0.05). And mitochondrial membrane damage with all sperm was significantly lower in semen treated with extenders magnetized at 2000 G than other groups during semen preservation for 168 h. The ability of semen to achieve successful in vitro fertilization was also not significantly different among the groups during preservation. However, when the semen was preserved for 168 h, the blastocyst formation rates were significantly higher at 6000 G compared to 0 and 2000 G (p < 0.05). In conclusion, these results suggest that highly magnetized semen extender could protect the sperm membrane from damage, and improve the ability of rates of in vitro blastocyst development and magnetized semen diluter is beneficial for long liquid preservation of boar semen.