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3.3.1. Abstract
CHAPTER 3.3
Routine semen analysis includes evaluation of concentration combined with seminal volume,
morphology and motility. Subjective analysis of these parameters is known to be inaccurate,
imprecise and subject to variability. Automated semen analysis could lead to an increased
standardization in and between laboratories but for that to happen automated devices need to be
validated. A new device, the sperm quality analyzer V equine (SQA-Ve) version 1.00.43, was
evaluated for its repeatability and agreement with light microscopy (LM), for raw and extended
equine semen. Results were compared with computer assisted sperm analysis (CASA), which was
also tested for its repeatability and agreement with LM. The SQA-Ve showed a good repeatability
and fine agreement for assessing sperm concentration of raw semen based on scatter and Bland-
Altman plots. This was in contrast with the motility parameters, which had a low repeatability.
Morphology assessment with SQA-Ve was poorly repeatable as well as in poor agreement with LM.
For extended semen, the findings were comparable. The SQA-Ve did well for concentration, whereas
for the motility parameters repeatability was only just acceptable, with however, no agreement with
LM. This sharply contrasted the CASA findings that were highly repeatable and almost in perfect
agreement with LM. Based on these findings, the tested version of the SQA-Ve is insufficiently
accurate to be used for analyzing raw or extended equine semen.
3.3.2. Introduction
Although a plethora of specialized tests is available for analyzing semen samples (Varner,
2008), a routine semen analysis includes the evaluation of concentration, seminal volume (Perreault,
2009), morphology and motility (Varner, 2008). Microscopical measurements of sperm numbers,
motility and morphology have been shown to be inaccurate and imprecise (Davis and Katz, 1993)
and subject to high subjectivity (Matson, 1995). In order to overcome these inaccuracies, automated
systems have been developed. In 1981, the Sperm Motility Analyzer was described by Bartoov et al.
(1981) as a practical tool to evaluate overall sperm quality. This device, in later articles called the
Sperm Quality Analyzer (SQA), registers fluctuations in optical density of light passing through a
capillary which contains the semen sample. These fluctuations are registered by a photometric cell
and converted to a numerical output. As such, the SQA does not recognize the actual sperm cells
during the analysis.
Computer-assisted semen analysis (CASA) was introduced both for humans and animal
species about two decades ago (Verstegen et al., 2002). Using the combination of a microscope and
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