Addition of Cholesterol-Loaded Cyclodextrins to the Thawing Extender: Effects on Boar Sperm Quality

Contents The aim of the present study was to evaluate the effect that the addition of cholesterol-loaded cyclodextrins (CLC) to the thawing extender has on the quality of frozen-thawed boar sperm. Pooled semen (n=5) from three boars was used for the experiments. The semen was cryopreserved with an egg-yolk-based extender, it was diluted after thawing in Beltsville thawing solution (BTS) supplemented with different concentrations of CLC (0, 12.5, 25, 50 or 100mg/500x10(6) sperm), and these samples were incubated at 37 degrees C for 150min. The following parameters of sperm quality were evaluated 30 and 150min after incubation: sperm with intact plasma membrane (SIPM; %), sperm with normal acrosomal ridge (NAR; %), total motile sperm (TMS; %), progressively motile sperm (PMS; %) and kinetic parameters. Both SIPM and NAR increased (p<0.05) when the thawing extender was supplemented with 12.5, 25 and 50mg CLC/500x10(6) sperm. Nevertheless, motility decreased (p<0.05) when the concentration of CLC exceeded 12.5mg CLC/500x10(6) sperm. In conclusion, our results suggest that the supplementation of thawing extenders with CLC improves sperm viability and reduces acrosome damage after freezing/thawing.