Accurate measurement of stallion spermatozoal concentration is important to
equine breeding operations. The hemacytometer is considered the standard for
measuring spermatozoal concentration but is time consuming and may be imprecise. The
flow cytometer is considered precise and accurate, but only practical for research
purposes due to sample preparation time and high cost. Photometric systems are
commonly used but can be inaccurate outside a relatively narrow concentration range
and can be rendered inaccurate in the presence of contaminants. A new instrument, the
NucleoCounter SP-100 is reported to enumerate spermatozoa at wider concentration
ranges and can identify spermatozoa in opaque semen extenders. Epididymal, neat (raw)
ejaculates, and ejaculates diluted in various semen extenders were analyzed with the
NucleoCounter, the Densimeter, the Spermacue, flow cytometric and
hemacytometric methods. Results were compared statistically by: 1) regression analysis,
2) the agreement of two instruments, whereby the difference in values between two
instruments was plotted on the y-axis against the mean of those values on the x-axis [26] and 3) a modified method that measured the percentage deviation, whereby the
percentage (of the difference in values between two instruments divided by the mean) of
the same two values was plotted on the y-axis against the mean value of the two
instruments on the x-axis.
The NucleoCounter showed more agreement with both the flow cytometer and
hemacytometer for epididymal, neat ejaculated and extended spermatozoa over a range
of concentrations than the Densimeter or the Spermacue. The NucleoCounter showed
more agreement with the flow cytometer for epididymal and neat ejaculated spermatozoa
and more agreement with the hemacytometer for spermatozoa diluted in semen
extenders. The Spermacue showed the least agreement with both standards for all
spermatozoal comparisons. All coefficients of variation for the flow cytometer,
hemacytometer and NucleoCounter were >10% for all spermatozoal comparisons.
This study indicates that the NucleoCounter shows more agreement with the flow
cytometer and hemacytometer than photometric systems when evaluated with
epididymal, neat ejaculated and extended spermatozoa. The instrument is also more
repeatable than either photometric system, but may be cost-prohibitive for some
operations.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-05-261 |
| Date | 16 January 2010 |
| Creators | Comerford, Kathryn L. |
| Contributors | Love, Charles |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis |
| Format | application/pdf |
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