Nicotinic Acid (Niacin) Supplementation in Cooling and Freezing Extenders Enhances Stallion Semen Characteristics.

The research article discusses the use of nicotinic acid (NA) or Niacin in preserving the qualities of stallion sperm during cooling and freezing processes. It found that Nicotinic acid can effectively safeguard sperm from damage during these processes, enhancing their post-thaw characteristics and allowing for longer storage without significant quality loss.

Methodology and Experiment

• The experiment utilized semen from five stallions, collected in six repeated sessions. In each of these sessions, semen samples from two stallions were pooled together.
• The researchers explored the impact of three concentrations of NA (10, 20, and 40 mM) on the cooled and frozen spermatozoa’s attributes – viability, plasma membrane or acrosome integrity, DNA fragmentation, lipid peroxidation, and total oxidant levels.
• The researchers also examined whether NA could help preserve the post-thaw sperm quality after 6 hours of cold storage before freezing.

Findings

• The researchers determined that NA at 20 and 40 mM concentrations could significantly improve multiple quality markers of stallion sperm during cold storage.
• However, they found no significant difference in the protective effects between the 20 mM and 40 mM concentrations for most of the measures, implying that a higher concentration may not guarantee an improved effect.
• NA also showed an ability to enhance the post-thaw stallion sperm quality at all investigated concentrations (10, 20, and 40 mM).

Negative Side-Effects at Higher Concentration

• Despite the generally positive effects, the study’s results indicate that a 40 mM concentration could negatively affect some post-thaw kinematic sperm parameters, cautioning against the use of excessive concentrations of NA.

Specific Benefits of Using Nicotinic Acid

• The research confirmed that using 10 and 20 mM concentrations of NA could help sustain the sperm’s cryo-tolerance, allowing it to be frozen up to 8 hours after collection without considerable deterioration in most of the post-thaw sperm quality measures.
• Furthermore, NA also demonstrated a capability to lower the level of lipid peroxidation and total reactive oxygen/nitrogen species in the cooled and frozen-thawed spermatozoa.

Conclusion

• Ultimately, the study concluded that nicotinic acid at a 20 mM concentration could be effectively utilized to preserve most of the stallion sperm quality measures throughout cold storage (42 hours, 5°C), enabling storage of cooled stallion semen for 6 hours before freezing without considerable deterioration of the post-thaw sperm quality.