Quality Improvement of Post-Thawed Stallion Epididymal Spermatozoa with Single Layer Centrifugation.

BACKGROUND

Epididymal sperm cryopreservation represents the ultimate option to preserve spermatozoa of valuable stallions.

OBJECTIVE

The study aims to evalute whether single layer centrifugation (SLC) prior to cryopreservation or after post-thawing improves the quality of stallion epididymal sperm.

MATERIALS AND METHODS

Epididymal sperms of stallions were harvested (N=20). Sperm samples were subjected to treatments: conventional centrifugation, SLC prior to cryopreservation (SLC-PC) or SLC post-thaw (SLC+). All samples were cryopreserved, thawed and evaluated. SLC+ were thawed, single layer cenrifuged and resuspended in freezing extender (SLC+F) or cooling extender (SLC+C). Total motility, progressive motility, morphology, mitochondrial functionality, membrane integrity and DNA integrity were evaluated.

RESULTS

SLC-PC and SLC+F yielded higher total motility, while SLC+F yielded the highest progressive motility. Mitochondrial functionality was significantly higher in all SLC groups. Membrane integrity was higher in SLC-PC. The percentage of morphologically normal spermatozoa was higher in SLC-PC and SLC+F.

CONCLUSION

SLC prior to cryopreservation or post-thaw improves the quality of stallion epididymal spermatozoa. When SLC is performed post-thaw, freezing extender is the best medium to resuspend the pelleted semen.