Effect of cold storage period on the quality of ram cauda epididymal spermatozoa recovered postmortem
Postmortem spermatozoa recovery is an important tool for harvesting germplasm from genetically meritorious animals and endangered species. The principal motive of this study was to find out whether ram spermatozoa within epididymides kept at 4 °C for 48 h retain their quality in terms of progressive motility, viability, and acrosomal status. Twenty-four testicles with attached epididymides were collected with 8 samples each processed at 0, 24, and 48 h of storage. A good number of motile spermatozoa could be recovered from epididymides by incision method with up to 48 h of storage, although their quality declined significantly (P < 0.05) as postmortem storage time increased (motility: 83.33 ± 1.05%, 63.33 ± 2.47%, and 44.17 ± 1.53%; and epididymal sperm output (millions): 3500.00 ± 73.97, 1220.00 ± 1.01, and 666.67 ± 19.78 for 0 (control), 24, and 48 h, respectively). Viability and intact acrosomes (%) were also acceptable, although they decreased significantly with up to 24 h of storage. In conclusion, ram epididymides could be stored at 4 °C for 48 h when epididymal spermatozoa cannot be immediately harvested and cryopreserved.
Key words: Cauda epididymides, spermatozoa, ram, cold storage