Postthaw Addition of Autologous Seminal Plasma Improves Sperm Motion Characteristics in Fair and Poor Freezer Stallions.

The research explores the addition of autologous seminal plasma to stallion semen after thawing from cryopreservation. It finds that this process enhances the motion characteristics of semen, particularly in stallions deemed to have ‘fair’ or ‘poor’ freezability, presenting a valuable new protocol for cryopreservation laboratories and veterinarians alike.

Objective and Methodology

• The researchers wanted to determine the effect of adding autologous seminal plasma to frozen-thawed stallion semen on its motion characteristics. They hypothesized that this process would improve the semen’s ability to move, particularly in stallions with ‘fair’ or ‘poor’ freezability.
• This study utilized the semen of four stallions with ‘fair’ freezability and three with ‘poor’ freezability. They used different combinations of seminal plasma and freezing extenders in a series of experiments to reach their conclusions.
• For each experiment, the semen samples were frozen, then thawed and diluted either with a semen extender or with various seminal plasma combinations. Then their motility and velocity were analyzed and compared.

Findings

• For the ‘fair’ freezer stallions, semen diluted with semen extender presented higher total and progressive motilities than plasma groups. However, for the ‘poor’ freezer stallions, there was no variability in motility among different groups.
• Upon comparing individual stallions, beneficial effects of seminal plasma on total or progressive motility were observed for two stallions.
• Velocity parameters and straightness dimensions were significantly improved in semen samples mixed with seminal plasma, especially for ‘fair’ freezer stallions. For ‘poor’ freezer stallions, such improvements were only significant in terms of velocity.

Conclusion and Recommendations

• The study’s findings suggest that adding autologous seminal plasma to frozen-thawed semen can enhance its mobility features, especially in stallions with ‘fair’ or ‘poor’ freezability.
• This discovery presents a valuable protocol for laboratories dealing with cryopreservation of stallion semen, as well as for veterinarians working with such stallions.