The relationship between sperm quality parameters and stallion fertility
Authors: Johannisson Anders, Cojkić Aleksandar, Morrell Jane M
Journal: Journal of Equine Veterinary Science
Summary
# Editorial Summary Johannisson and colleagues evaluated sperm gene expression in 40 Criollo stallions to identify molecular markers predictive of fertility, categorising animals by pregnancy rates (≥50% versus <50% per cycle across breeding seasons) and analysing semen using computer-assisted sperm analysis alongside membrane integrity assessment. Phospholipase C zeta (PLCζ) emerged as a significant biomarker, with expression levels significantly higher in high-fertility stallions (P = 0.012) and showing strong positive correlations with conception rate, total motility, progressive motility, and plasmatic membrane functionality; crucially, a linear regression model demonstrated PLCζ expression independently predicted pregnancy rate (P = 0.003), as did both total and progressive motility (P < 0.001 for each). Two other examined genes—WBP2NL and TNF-α—showed no meaningful associations with seminal quality or fertility outcomes. For practitioners, these findings suggest that measuring PLCζ gene expression alongside conventional semen parameters could refine stallion fertility assessment and guide breeding decisions, particularly when distinguishing genuinely subfertile animals from those with borderline conventional semen quality.
Read the full abstract on PubMed
Practical Takeaways
- •PLCζ gene expression could serve as a practical biomarker to identify subfertile stallions and predict their breeding potential before committing breeding resources
- •Standard CASA analysis parameters (total and progressive motility) remain useful predictors of fertility and should continue to be part of routine stallion breeding soundness evaluation
- •Stallions with pregnancy rates below 50% may benefit from semen analysis including motility assessment and consideration of PLCζ testing to determine suitability for breeding programs
Key Findings
- •PLCζ gene expression in spermatozoa positively correlates with conception rate and shows significant linear regression with pregnancy rate (P = 0.003)
- •PLCζ expression was significantly higher in high-fertility stallions (≥50% pregnancy rate) compared to low-fertility stallions <50% (P = 0.012)
- •Total motility and progressive motility both show positive correlation with pregnancy rate (P < 0.001 for both)
- •WBP2NL and TNF-α gene expression did not correlate with seminal quality or stallion fertility