Ejaculated compared with epididymal stallion sperm vitrification.

The research analyzed the effectiveness of using trehalose and lactose extenders during the vitrification process of stallion sperm, both ejaculated and from the epididymis. The study found that using trehalose in the vitrification process of epididymal sperm resulted in higher sperm motility, suggesting it could be beneficial for long-term sperm storage. However, ejaculated sperm samples subjected to vitrification showed reduced viability compared to conventionally frozen samples.

Objective and Methods of the Study

• This study aimed to investigate the effects of trehalose and lactose extenders on the vitrification of ejaculated and epididymal stallion sperm. Vitrification is a process of cryopreservation that involves the conversion of a fluid into a solid, glass-like state without forming ice crystals, which can be beneficial for the preservation of sperm’s biological functions.
• Ejaculated semen samples were collected from seven fertile stallions, and epididymal samples were collected from ten stallions post-mortem.
• Vitrification was carried out using extenders, INRA 96® and bovine serum albumin, with either trehalose or lactose. For each type and method of sperm collection, control samples were also stored using traditional freezing methods.

Findings and Results

• The study found that vitrification of epididymal sperm with either trehalose (EPT) or lactose (EPL) resulted in more significant progressive sperm motility than the control sample (EPC), meaning these sperm moved forward more effectively. Specifically, post-thaw motility for sperm in the EPT group was significantly higher compared to sperm in the EPL group.
• However, the vitrification of ejaculated sperm led to less viable cells compared to those stored using the conventional freezing method. Viable cells are ones that can function correctly and have the potential to fertilize an egg.

Conclusion and Significance

• The research concludes that vitrification of epididymal stallion sperm, particularly using trehalose as an extender, could serve as a fruitful alternative for the long-term preservation of economically valuable sperm samples due to its preservation of progressive motility.
• Contrarily, the vitrification of ejaculated stallion sperm yielded lesser motility and viability rates compared to the samples that underwent traditional freezing, indicating that current vitrification methods may not be best suited for these types of sperm samples.