Effect of Mare Colostrum in Extenders for Freezing Stallion Semen.
Authors: Álvarez Cristina, Luño Victoria, González Noelia, Guerra Pilar, Gil Lydia
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Mare Colostrum as a Cryoprotectant in Stallion Semen Freezing Cryopreservation of stallion semen remains a cornerstone of equine breeding programmes, yet post-thaw sperm quality is highly variable depending on extender composition. Álvarez and colleagues investigated whether supplementing lactose-based freezing extenders with mare colostrum (20%) could improve outcomes compared to conventional egg-yolk or commercial BotuCrio media, using semen pooled from nine fertile stallions and evaluated via computer-assisted motility analysis, viability staining, acrosome integrity assessment, plasma membrane function testing, and DNA fragmentation evaluation. Whilst total motility, acrosome integrity and DNA damage showed no significant differences between groups post-thaw, the mare colostrum extender demonstrated superior protection against cold-shock injury, matching BotuCrio and significantly outperforming egg-yolk on plasma membrane functionality (HOS test) and kinematic parameters including linearity, straightness and wobble—though egg-yolk extenders preserved viability most effectively overall. For practitioners involved in semen collection and cryopreservation, these results suggest mare colostrum offers a promising natural alternative to conventional additives, particularly for protecting structural membrane integrity, though the choice of extender may need tailoring based on whether viability or motility parameters are prioritised for individual breeding programmes.
Read the full abstract on PubMed
Practical Takeaways
- •Mare colostrum offers a potentially cost-effective and practical alternative to egg yolk as a cryoprotectant in stallion semen freezing protocols
- •Commercial extenders like BotuCrio remain superior for kinematics parameters; selection should match breeding program priorities (motility vs. viability)
- •Using mare colostrum as a supplement could provide a readily available source material in equine breeding facilities, though comparative cost-benefit analysis is needed
Key Findings
- •Mare colostrum (20%) in lactose-based extender protected sperm against cold-shock and showed comparable results to commercial extenders
- •BotuCrio demonstrated significantly higher kinematics parameters (linearity, straightness) compared to lactose-based extenders (P < 0.05)
- •Lactose egg yolk extender yielded significantly better sperm viability rates than mare colostrum or commercial extenders (P < 0.05)
- •No significant differences were found in total motility, acrosome integrity, or DNA fragmentation among the three extender groups