Chelation of trace elements in preservation medium influences the quality of boar spermatozoa during liquid preservation at 5°C for 4 weeks.

BACKGROUND: The addition of a metal chelator, ethylenediaminetetraacetic acid (EDTA), to semen extender has the purpose of capturing trace element ions. OBJECTIVE: This study was conducted to evaluate the effects of EDTA on the quality and in vitro fertilisability of liquid-preserved boar spermatozoa. METHODS: In Experiment 1, semen samples were preserved in the semen extender supplemented with 0, 3, 6, or 12 mM of Na-EDTA at 5 degree C for 4 weeks. In Experiment 2, semen samples were preserved in the extender supplemented with 3 mM of Na-EDTA, Ca-EDTA, or Zn-EDTA and without chelator EDTA. RESULTS: When Na-EDTA was used as a chelating substance in the extender, 3 mM was a most suitable concentration for sperm motility and viability after cold preservation. The supplementation of 3 mM Ca-EDTA had advantages regarding sperm motility, viability and plasma membrane integrity. CONCLUSION: Our findings indicate that 3 mM Ca-EDTA is the most suitable metal-chelating substance for the liquid preservation of boar semen.