Freezing of both ejaculated and epididymal spermatozoa are currently a subject of interest with the purpose of establishing an efficient gene banking model for valuable animals or endangered species. Therefore, the mean goal of this study has been carried out in two different parts; the effects of different storage lengths )0, 1.5 and 5 h) at 5 ºC on ram epididymal spermatozoa and the addition of different cryoprotectants to extenders their freezability. The evaluated characteristics of sperm cells included the rates of motility, progressive motility, viability, normal acrosome, recovery rate and released hyaluronidase enzyme of storage length at 5°C and froze-thawed epididymis spermatozoa. The results of first part indicate that that with increasing of storage lengths from 0 to 3 h at 5 ºC, the motility, progressive motility, viability and recovery rate of stored spermatozoa decreased significantly (P<0.05), but the acrosome integrity and the rate of released hyaluronidase enzyme present significantly no effects (P>0.05). The results of second part demonstrate that the addition of trehalose and sucrose to basic diluent improved significantly (p<0.05) the quality of frozen-thawed spermatozoa. Regarding the motility, progressive motility, viability, the rate of released hyaluronidase, the BSA and control extenders presented significantly (p>0.05) no differences, but the both were significantly (p<0.05) better then extender supplemented with DMSO. In addition, the results of control diluent and extenders containing sucrose, BSA and DMSO significantly no differences (P>0.05) for acrosome integrity. In conclusion, this study indicated that the increasing of storage length decreased significantly the quality of epididymal spermatozoa, but the quality has been improved when the extenders supplemented with sugars. However, studies are still needed to determine the effect of using the froze-thawed epidydimal spermatozoa in fertilizing process
