Majid Alaeipour - Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran
Mohammad Roostaei-Ali Mehr - Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran

This study was conducted to evaluate the effect of replacing glycerol with erythritol on cryopreservation of ram spermatozoa. Semen samples (n=24) were collected from four rams in six times. In each session, the collected ejaculates (n=4) were pooled and split into 12 equal parts. The amount of 0.032 M glycerol (G32E0, equal to 3% glycerol), 0.016 M glycerol and 0.016 M erythritol (G16E16), 0.008 M glycerol and 0.024 M erythritol (G8E24), 0.032 M erythritol (G0E32), 0.054 M glycerol (G54E0, equal to 5% glycerol), 0.027 M glycerol and 0.027 M erythritol (G27E27), 0.013 M glycerol and 0.041 M erythritol (G13E41), 0.054 M erythritol (G0E54), 0.076 M glycerol (G76E0, equal to 7% glycerol ), 0.038 M glycerol and 0.038 M erythritol (G38E38), 0.019 M glycerol and 0.057 M erythritol (G19E57) and 0.076 M erythritol (G0E76) were added. The diluted samples were frozen using standard protocol. After thawing, the samples were incubated at 37°C for 6 h. Results showed that progressive sperm motility and acrosome integrity were higher in G13E41 (18.85 % and 27.41 %, respectively) than treatments that contained only glycerol at 6 h (p < 0.05). At the level of 0.032 and 0.054 M cryoprotectant, the highest of total sperm motility was observed in G8E24 (19.16 %) and G13E41 (18.85 %) at 6 h, respectively (p < 0.05). Therefore, the quality of frozen-thawed ram spermatozoa can be improved by using the mixture of 0.013 M glycerol plus 0.041 M erythritol or 0.008 M glycerol plus 0.024 M erythritol.

Cryopreservation, Polyol, Glycerol, Ram sperm