Optimization of donkey sperm vitrification: Effect of sucrose, sperm concentration, volume and package (0.25 and 0.5 mL straws).

The research study aimed to optimize the process of preserving donkey sperm cells through vitrification, focusing on factors such as the composition of the extender, sperm concentration, volume of preservation and type of storage container. Results showed that an egg-yolk extender with 0.1 M sucrose, a concentration of 300 million sperm/mL, and storage in 0.25 mL straws yielded the best results for sperm quality.

Objective and Experimental Design

• The primary aim of this research was to optimize the process of vitrification (quick freezing) for the long-term preservation of donkey sperm, with an emphasis on certain factors that could potentially affect the process outcomes.
• The researchers carried out a series of experiments, varying the extender (substance that nourishes and protects the sperm), sperm concentration, volume of storage and the type of storage vessel.

Results and Findings

• In the first experiment, the researchers found that an extender supplemented with 0.1 M sucrose yielded better results, especially when egg-yolk was present in the extender. This was evidenced by higher total and progressive motility percentages, which are important parameters for sperm health and viability.
• In the second experiment, they found no significant impact of the sperm concentrations on vitrification outcomes. Regardless of the concentration used (100, 200, or 300 million sperm/mL), the post-vitrification results were similar, indicating that sperm concentration isn’t a critical factor for effective vitrification in this context.
• Thirdly, researchers tested different sperm storage volumes (100, 160, and 200 μL) and storage vessels (0.25 and 0.5 mL straws). They found that a small volume of 0.25 mL stored in straws yielded higher sperm motility percentages, plasma membrane integrity, and acrosome integrity, indicating that smaller storage volume and certain straw types can help better preserve sperm quality after vitrification.

Conclusion and Implications

• Based on these results, the optimal parameters for donkey sperm vitrification were identified as using an extender containing egg-yolk and 0.1 M sucrose, a sperm concentration of 300 million sperm/mL, and 0.25 mL straws for storage.
• This research provides valuable insights and parameters that could be beneficial for the efficient and successful vitrification of donkey sperm, contributing to effective sperm preservation techniques for fertility or conservation purposes.