Semen Cryopreservation and Sperm Quality in Canine Reproduction

Semen cryopreservation has become an indispensable tool in canine breeding programmes, genetic resource banking and conservation of rare or endangered canid species. By cooling and storing ejaculated sperm at ultra‐low temperatures, practitioners can decouple collection from insemination, extend the availability of valuable genetic material and support assisted reproductive techniques. However, the freeze–thaw cycle imposes thermal, osmotic and mechanical stresses that compromise sperm motility, disrupt membrane integrity, induce oxidative damage and impair DNA and acrosomal functions. Contemporary research seeks to refine extenders, optimise cooling rates and introduce protective agents or co‐culture systems to mitigate cryoinjury. Progress in this field promises to enhance fertility outcomes, support selective breeding strategies and facilitate translational insights relevant to other mammalian species.

Research from Nature Portfolio

Recent studies have demonstrated that the inclusion of adipose‐derived mesenchymal stem cells in canine semen extenders can significantly improve post‐thaw sperm quality. At an optimal concentration of 2.5 × 10^6 cells/mL, treated samples exhibited higher total and progressive motility, increased proportions of live sperm and better preservation of plasma membrane and acrosome structure compared with controls. Molecular analyses revealed upregulated expression of membrane‐repair and chromatin‐stabilising proteins, indicating that secreted factors from mesenchymal stem cells confer cryoprotection by bolstering membrane resilience and reducing fragmentation of nuclear material. This co‐culture approach offers a novel strategy to attenuate cryoinjury and enhance fertilising potential.

Semen Cryopreservation and Sperm Quality in Canine Reproduction publication trend

The graph below shows the total number of articles in semen cryopreservation and sperm quality in canine reproduction across all publications each year (not limited to Nature Index journals).

Technical terms

Cryopreservation: The process of preserving cells or tissues at ultra‐low temperatures to halt metabolic activity and maintain viability for future use.

Extender: A buffered solution containing cryoprotectants, nutrients and stabilisers used to dilute and protect semen during cooling and freezing.

Acrosome integrity: The intactness of the cap‐like structure over the sperm nucleus, essential for enzyme release and successful penetration of the oocyte.

Reactive oxygen species (ROS): Highly reactive molecules derived from oxygen that can damage lipids, proteins and DNA in sperm cells if not neutralised by antioxidants.

Mesenchymal stem cells: Multipotent stromal cells capable of secreting bioactive factors that enhance membrane repair, reduce oxidative stress and support cellular resilience during cryopreservation.

References

1. Improved viability and fertility of frozen-thawed dog sperm using adipose-derived mesenchymal stem cells. Scientific Reports (2020).
2. Cryoprotective Effects of Ergothioneine and Isoespintanol on Canine Semen. Animals (2021).
3. Effect of Aqueous Extract of Maca Addition to an Extender for Chilled Canine Semen. Animals (2022).
4. Effects of age, size and season on cryotolerance of dog semen – A retrospective analysis. Animal Reproduction Science (2021).