Automated morphometric analysis of stallion spermatozoa.

The research is about the development and testing of a new method and instrument for preparing and analyzing stallion spermatozoon morphology to predict fertility. Automated methods were used to increase the accuracy and reliability of data collected.

Research context and goals

• The study addresses an issue in stallion fertility research that arises from variability in microscope slides used for sperm analysis and subjective techniques used to analyze these slides.
• The variability causes reduced statistical power of such studies and hence, impedes the use of spermatozoon morphology to predict fertility.
• The goal of the research was to develop a standardized specimen preparation method to create homogenous stallion spermatozoon morphologic smears, and use a new automated instrument for unbiased analysis.

Methodology and findings

• The newly developed method generated a standard spermatozoon concentration and decreased field-to-field variation in the number of spermatozoa analyzed.
• Measurements of spermatozoon head dimensions from clinically normal, fertile stallions revealed slight but statistically significant differences between stallions.
• There was minimal variation in measurements between replicate slides within stallions, suggesting that repeated slide analysis may not be necessary for such stallions.

Results and significance

• General coefficients of variation were less than 11% between stallions, and less than 4% within stallions. This data implies high reliability in the reading, and suggests it could be broadly applicable across a range of stallions.
• This study reveals that a higher degree of statistical power can be achieved by using the new standardized specimen preparation and objective analysis techniques.
• Furthermore, it allows for the detection of minor differences between clinically normal stallions and potentially, accurate detection of abnormal fertility – also known as subfertility – in stallions.