Sperm head morphometry analysis of ejaculate and dismount stallion semen samples

Area of Science:

• Veterinary Science
• Reproductive Biology
• Animal Science

Background:

• Clinical detection of stallion subfertility relies on semen evaluation.
• Conventional methods involve subjective assessment of sperm concentration, motility, and morphology.
• Automated sperm morphology analysis (ASMA) offers objective evaluation.

Purpose of the Study:

• To determine if morphometric measurements of sperm heads from collected and dismount samples are similar.
• To assess the representativeness of post-ejaculate dismount samples for fertility evaluation.

Main Methods:

• Ejaculate samples were collected from ten stallions using an artificial vagina.
• Post-ejaculate dismount samples were obtained from the penis head.
• Sperm heads were analyzed using computer automated sperm morphometry analysis (ASMA) after staining.

Main Results:

• No significant differences were found in sperm head length, width, width/length ratio, area, or perimeter between collected and dismount samples (P > 0.10).
• Coefficients of variation for sperm head measurements also showed no significant differences between sample types.
• Mean values for collected samples: length=5.96 µM, width=2.95 µM, area=13.31 µM², perimeter=15.54 µM.
• Mean values for dismount samples: length=6.06 µM, width=2.98 µM, area=13.65 µM², perimeter=15.74 µM.

Conclusions:

• Sperm head measurements from dismount semen samples are representative of the entire ejaculate.
• Dismount samples can be reliably used for fertility studies and clinical assessments.
• This supports the development of objective criteria for stallion sperm head morphometry.