Impact of Zeolite Addition in Semen Extender on Rabbit Sperm Quality after Cryopreservation

The aim of this study was to evaluate the effect of adding zeolite mineral in semen extender on rabbit sperm cryopreservation. Ten healthy, fertile rabbit bucks were used, and the ejaculates were obtained using an artificial vagina. Semen of all bucks were pooled and diluted in a tris-yolk fructose (TYF) extender supplemented with zeolite at concentration of 0 (control) and 1% (w/v) for a final sperm concentration of 25 x 106 sperm cells/ ml. Diluted semen was packed in straws (0.25 ml) and stored in liquid nitrogen (-196 °C) for one month. After thawing, semen of each treatment was evaluated for sperm quality parameters, including sperm progressive motility, livability, morphological abnormalities and plasma membrane integrity. Apoptosis and sperm ultrastructure were also examined. Total antioxidant capacity and lipid peroxidation markers were determined in extender after thawing. Results showed that zeolite had a positive effect (P < 0.05) on sperm characteristics (progressive motility, livability and membrane integrity) after equilibration period and post-thawing as compared with the control. Percentage of viable sperm increased (P < 0.05), while percentages of early apoptotic, apoptotic and necrotic sperm cells decreased (P < 0.05) in treatment of zeolite as compared to control. In contrary, total antioxidants capacity in extender decreased (P < 0.05) and malondialdhyde and H2O2 concentration increased (P < 0.05) in treatment of zeolite compared to control. In conclusion, addition of semen extender with zeolite improved post-thaw sperm quality of rabbit by enhancing sperm characteristics, reducing apoptosis and sperm damage occurring by cryopreservation.