Supplementation of Fructose on Porcine Sperm Improves Characteristics on Frozen-Thawed Sperm

Using an alternative energy source for spermatozoa during in vitro fertilization could be responsible for the high incidence of polyspermic penetration in porcine oocytes. The objective of this study was to evaluate the effects of supplementing 11.0 mM D-(+)-glucose or 11.0 mM D-(-)-fructose as the energy source during the thawing and culture procedure of frozen-thawed semen. Sperm was evaluated for forward progressive motility, viability, and the ability to undergo the acrosome reaction (capacitation) at 0, 2, 4, 6 h after thawing. The effects of supplementing 11.0 mM D-(+)-glucose or 11.0 mM D-(-)-fructose during the thawing and in vitro fertilization procedures were evaluated on fertilization, polyspermic penetration, male pronuclear (MPN) formation, and embryonic development. Sperm supplemented with fructose had significantly higher (P < 0.05) forward progressive motility and viability compared to sperm supplemented with glucose at 0, 2, 1nd 4 h after thawing. Additionally, sperm supplemented with fructose had significantly higher ability (P < 0.05) to undergo the acrosome reaction compared to sperm supplemented with glucose at each time measurement after thawing. There were no significant differences observed in fertilization, polyspermic penetration, or MPN formation rates between oocytes (n = 41) fertilized with either glucose or fructose supplemented sperm. Oocytes (n = 478) fertilized with sperm supplemented with fructose had a significantly higher (P < 0.05) percent of embryos cleaved by 48 h after IVF (80.00% ± 4.23) compared to those that were supplemented with fructose (69.76 ± 3.87). There was a no difference in blastocyst formation rate at 144 h after IVF between the treatment groups. The results indicate that supplementing frozen-thawed boar semen with fructose rather than glucose improves spermatozoan characteristics but does not have an affect on the in vitro production of pig embryos.