Capacitation, acrosome function and chromatin structure in stallion sperm.

Area of Science:

• Veterinary Science
• Animal Reproduction
• Equine Fertility

Background:

• Stallion fertility is notably lower and more variable than in other livestock species.
• Selection criteria for stallions often overlook fertility, focusing instead on pedigree, appearance, and athletic performance.
• Obtaining accurate fertility data is difficult due to limited breeding numbers and confounding mare/management factors.

Purpose of the Study:

• To review advanced sperm assays for predicting stallion fertility.
• To assess the utility of these assays in identifying stallions with high fertility potential.
• To improve pre-breeding career fertility predictions in stallions.

Main Methods:

• Review of literature on assays for capacitated, acrosome-reacted, and DNA-damaged sperm.
• Assessment of the predictive value of these assays for stallion fertility.
• Comparison of novel assays with traditional breeding soundness examinations (BSE).

Main Results:

• Traditional BSE has limited success in predicting fertility, often only identifying stallions with obvious sub-fertility issues.
• Novel sperm assays targeting sperm capacitation, acrosome reaction, and DNA integrity offer potential for more accurate fertility prediction.
• These advanced assays may help identify stallions with sub-optimal fertility that are missed by routine BSE.

Conclusions:

• Current breeding soundness examinations are insufficient for accurately predicting stallion fertility.
• Advanced sperm assays, including those assessing sperm function and DNA integrity, hold significant promise for improving fertility predictions.
• Implementing these assays could enhance stallion selection and reproductive success in equine breeding programs.