Semen Cryopreservation Techniques in Avian Species

Semen cryopreservation in birds underpins both the conservation of genetic diversity and the optimisation of breeding programmes. Avian spermatozoa are highly susceptible to freeze–thaw damage owing to their slender flagella, high proportion of polyunsaturated fatty acids and limited antioxidant defence. Conventional protocols combine semen dilution with an extender containing cryoprotectants (such as glycerol or dimethyl sulphoxide), careful equilibration, controlled cooling, storage in liquid nitrogen and rapid thawing. Key determinants of success include the choice and concentration of cryoprotectant, the composition of the extender (nutrients, buffers and antioxidants), the freezing rate and the thawing regime. Contemporary studies employ omics methods to elucidate molecular pathways of freeze–thaw injury and to tailor extenders for specific breeds or species. Emerging strategies focus on modulating intracellular calcium, optimising reactive oxygen species scavenging and applying decision-tree algorithms to predict post-thaw performance. Together, these advances are broadening the applicability of cryobanking across poultry lines, game species and endangered galliformes, with global implications for food security, biodiversity preservation and research on reproductive biology.

Research from Nature Portfolio

Recent studies have demonstrated that transient reduction of intracellular calcium in liquid-stored chicken semen can markedly extend fertility. By incorporating extracellular and intracellular calcium chelators into semen extenders, researchers achieved prolonged in vivo fertility despite standard storage durations. Mechanistic investigation revealed that regulation of [Ca2+]i coordinates mitochondrial metabolism and ATP turnover, delivering a bimodal control of dynein ATPase activity. Initial activation by chelation is followed by suppression through cytoplasmic acidification, thereby stabilising motility and extending fertilising capacity. This work not only advances liquid-storage technologies for poultry semen but also sheds light on the physiological basis of sperm storage within the female reproductive tract.

Semen Cryopreservation Techniques in Avian Species publication trend

The graph below shows the total number of articles in semen cryopreservation techniques in avian species across all publications each year (not limited to Nature Index journals).

Technical terms

Cryoprotectant: A compound (e.g. glycerol) added to prevent ice crystal formation and membrane damage during freezing.

Equilibration time: The period that sperm remain in contact with cryoprotectants before the onset of freezing.

Liquid semen extender: A nutrient-rich solution used to dilute and stabilise semen during storage or transport.

Reactive oxygen species (ROS): Highly reactive oxygen-containing molecules that can induce lipid peroxidation and cellular damage.

Calcium chelator: A molecule that binds calcium ions, thereby modulating intracellular signalling and metabolism.

Osmolality: The concentration of solutes in a solution, influencing water movement across cell membranes.

Post-thaw viability: The proportion of sperm that retain normal structure and function after freezing and thawing.

References

1. Effect of Supplementation of a Cryopreservation Extender with Pectoliv30 on Post-Thawing Semen Quality Parameters in Rooster Species. Antioxidants (2024).
2. Arresting calcium-regulated sperm metabolic dynamics enables prolonged fertility in poultry liquid semen storage. Scientific Reports (2023).
3. Chicken Sperm Cryopreservation: Review of Techniques, Freezing Damage, and Freezability Mechanisms. Agriculture (2023).
4. Poultry genetic heritage cryopreservation and reconstruction: advancement and future challenges. Journal of Animal Science and Biotechnology (2022).