Consequences of butylated hydroxytoluene in the freezing extender on post-thaw characteristics of stallion spermatozoa in vitro.

The research examined the impact of a lipid soluble antioxidant known as butylated hydroxytoluene (BHT) on the quality of frozen stallion sperm. The study found that BHT supplementation in freezing extenders had no significant effect on any evaluated post-thaw sperm parameters.

Research Procedures

• Semen samples were collected from six pure Spanish stallions. Each ejaculate was divided into two subsamples: one was preserved in a commercial extender mixed with the antioxidant butylated hydroxytoluene (BHT), and the other subsample acted as a control.
• The sperm samples were then cryopreserved (frozen) and stored for a minimum of four weeks.
• Post-thaw analysis: After the storage period, the sperm samples were thawed and evaluated for quality. Key parameters included sperm motility and kinematics, membrane and acrosome integrity, and mitochondrial membrane potential. Computer-assisted sperm analysis (CASA) was utilized to assess sperm motility and kinematics, while flow cytometry was used to determine membrane and acrosome integrity and mitochondrial membrane potential.

Research Findings

• The research findings indicated a significant variation in the post-thaw sperm quality across different stallions.
• Notably, the supplementation of the freezing extender with BHT had no significant effect on any of the examined sperm parameters post-thaw. This suggests that the use of BHT in the freezing process does not impact the overall quality and integrity of cryopreserved stallion sperm.

Significance of the Study

• This research contributes valuable findings to the existing body of knowledge related to the quality and vitality of cryopreserved stallion sperm.
• The study’s conclusions could have implications for veterinary reproductive medicine and methods used to freeze and store stallion sperm. Despite BHT’s antioxidant properties, its use does not appear to influence the quality of frozen stallion sperm, suggesting the need for further research into other potential additives or methods to optimize sperm quality post-thaw.