Which fields under a coverslip should one assess to estimate sperm motility?

Area of Science:

• Veterinary Reproduction
• Spermatozoa Motility Analysis

Background:

• Accurate estimation of bull sperm motility is crucial for artificial insemination programs.
• Field assessments often rely on coverslip microscopy, necessitating standardized methods for reliable results.

Purpose of the Study:

• To identify the optimal combination of microscopic fields under a coverslip for estimating bull sperm motility.
• To compare coverslip motility measurements with those obtained from a computer-assisted sperm analyzer (CASA) chamber.

Main Methods:

• Bull semen motility was assessed using a Hamilton Thorne IVOS CASA system.
• Motility was measured in 12 fields along the coverslip radius and 8 fields in a Leja 4 chamber.
• Concordance correlation coefficients (CCC) were calculated to compare coverslip field combinations against the chamber gold standard.

Main Results:

• The average motility across all 12 coverslip fields best reproduced chamber motility.
• Averages from Fields 2-4 and Fields 2 & 4 showed comparable reproducibility to all 12 fields, except for total motile sperm.
• Using Fields 2 & 4, 50% of estimates were within 6% of chamber values for total motile sperm.

Conclusions:

• Averaging motility across all 12 fields under a coverslip provides the most accurate estimation of bull sperm motility.
• The average of Fields 2 and 4 is a practical alternative for field estimations, offering reasonable accuracy.