Automatic evaluation of ram sperm morphometry

Area of Science:

• Veterinary Science
• Reproductive Biology
• Biotechnology

Background:

• Sperm morphometry is crucial for assessing male fertility.
• Traditional methods for sperm analysis can be time-consuming and subjective.
• Objective and automated assessment of sperm parameters is needed.

Purpose of the Study:

• To develop and validate a novel automated method for ram sperm head morphometry using fluorescence microscopy and image analysis.
• To evaluate the effects of air-drying and different fixation methods (glutaraldehyde, methanol) on sperm morphometric parameters.
• To compare the new automated method with a conventional CASA-Morph (CASMA) system.

Main Methods:

• Ejaculates from rams were processed fresh, air-dried, or fixed with glutaraldehyde (GLUT) or methanol (MET).
• Fluorescence microscopy (Hoechst 33342) and ImageJ software were used for automated sperm head analysis.
• The developed method was compared against a conventional CASMA method (Hemacolor staining, ISAS software).

Main Results:

• The automated method provided fast and precise analysis of sperm head morphometry.
• Air-drying significantly decreased sperm head dimensions (area reduced by 9.1%).
• Glutaraldehyde fixation yielded morphometric results closest to fresh sperm and improved image quality compared to drying or methanol fixation.
• The new automated method analyzed a higher percentage of sperm (100%) compared to CASMA (93%) and showed significant correlations for all parameters.

Conclusions:

• Automated sperm morphometry using fluorescence microscopy and image analysis is feasible and efficient for routine semen analysis.
• Glutaraldehyde fixation is recommended for optimal sperm morphometry assessment in rams.
• The impact of drying and fixation on sperm morphometry may be less significant than previously assumed, especially with advanced automated methods.