Supplementation of Beltsville Extender with Plant-Origin Cryoprotectant for Cryopreservation of Rooster Se-men

Background: The avian sperm is susceptible to sever dam-ages during the freeze-thaw process due to high sensitivity to cold shock. Integrity of the rooster sperm membrane should be protected during freeze-thaw process. Extenders play an impor-tant role to reduce detrimental effects of freezing on sperm due to their stabilization effects on the sperm plasma membrane. Soybean lecithin is a novel plant-origin cryoprotectant that can protect sperm during freeze- thaw process. This cryoprotectant has not been assess in combination with Beltsville extender for rooster semen freezing. The aim of present study was to assess rooster sperm parameters after cryopreservation in Beltsville extender supplemented with different concentrations of soy-bean lecithin (SL) compared to Beltsville extender supplement with different concentrations of egg yolk (EY).Materials and Methods: Semen samples were collected twice a week from ten roosters. Then samples were pooled to elimi-nate individual difference and subsequently divided into 5 equal parts to be diluted with Beltsville Extenders containing different cryoprotectants as follow: 0.5% SL, 1% SL, 5% EY, 10% EY and 15 % EY. The diluted semen was gradually cooled to 4°C for 3 hours. Then cooled semen was loaded into 0.5-mL straws and they were exposed to liquid nitrogen vapor for 10 min, plunged into liquid nitrogen (LN2), and stored LN2 until thawed and used for evaluation of sperm parameters.Results: The highest significant percentage of total and pro-gressive motility were obtained in Beltsville supplemented with 1% SL (P<0.05). 0.5% SL produced the lowest significant per-centage of motility and viability (P<0.05). Between extenders containing egg yolk, 15% egg yolk produced the higher motility and viability of thawed sperm compared to 5% and 10% EY.Conclusion: It seems that replacement of egg yolk by soybean lecithin in Beltsville extender may produce the higher quality of frozen-thawed semen. According to the result, lecithin at con-centration of 1%, improves the motility and viability of rooster semen during cryopreservation.

Keywords:

Cryopreservation , Phospholipids , Antioxidant