In vitro effect of various cryoprotectants on the semen quality of endangered Oravka chicken.

We aimed to compare the effect of three different permeating cryoprotectants on the post-thaw spermatozoa quality. Pooled semen from Oravka cock line (n = 6) was diluted in Kobidil+ extender and frozen in cryoprotectant solutions containing 8% dimethylsulfoxide (DMSO), 8% ethylene glycol (EG) or 8% glycerol (GL) in liquid nitrogen vapours before being plunged into the liquid nitrogen. Spermatozoa motility parameters were assessed in vitro after freezing-thawing by a computer-assisted semen analysis (CASA) system and viability status was examined using fluorescent probes.