Effect of egg yolk concentrations on cryopreservation of boar semen.

The present experiment was conducted to investigate the effects of egg yolk on cryopreservation of boar semen by screening the best concentration of egg yolk in freezing boar semen.Different percentages(20,25 and 30%) of egg yolk were added to freeze diluted boar semen,and the quality of semen before diluting,after balancing and freezing were compared using sperm viability,motility,velocity of activity path,velocity of circle locus,velocity of straight locus,etc.The results showed that there were no significant differences in five velocity indices of sperm on adding different concentrations of egg yolk in boar semen freezing dilution after diluting,balancing and refreezing.Therefore,increasing concentration of egg yolk for boar semen freezing dilution could not enhance the quality of semen,and the 20% concentration of egg yolk in boar semen freezing dilution was found to be the best.