Bedömning av spermiemotilitet i färsk, kyld samt selekterad hingstsperma med Qualisperm
This EEF-project is a part of a larger project at SLU, Division of Reproduction,
Dept of Clinical Science, with the intention of developing and evaluating new
methods for the assessment of stallion semen quality. Over the last 10 years there
has been an increase in the use of artificial insemination with cooled semen in
Swedish horse breeding. At the same time, foaling rates have decreased. This has
lead to a need for new and better methods of assessing the quality of stallion
semen. This EEF-project was based on an objective method to calculate motility,
with QualispermTM, in fresh and cooled stallion semen, and after selection.
Today sperm motility evaluation is mainly done subjectively by visual assessment
with a light microscope, and the correlation between these motility results and
fertility have varied. Therefore, there have been a number of objective methods
designed, for example CASA (Computer Assisted Semen Analysis) where
QualispermTM (Biophos AG, Switzerland) is a new system based on different
principles compared to earlier CASA-systems. While other CASA-machines
takes a series of photographs and the trajectories are used to separate the sperm
tracks into categories of different motility patterns, QualispermTM determines the
number of particles (spermatozoa) crossing fields of view, yielding a regression
fluctuation algorithm of sperm numbers and translation classes. Furthermore it
analyzes thousands of spermatozoa per sample compared to other CASAmachines
where often only a couple of hundred spermatozoa are measured.
QualispermTM is also easier to use than other CASA-machines, which makes it
more suitable for use out in the field.
This EEF-project was carried out on the national stud at Flyinge during three
weeks in the summer of 2007. Three or four ejaculates /stallion from 10 stallions
where analysed during 3 days for subjective and objective motility in fresh and
cooled semen and after selection by centrifugation. The semen was kept both in
room temperature and chilled at + 5 ° C, to study how the temperature would
affect the motility.
The statistical analysis showed that there was a significant correlation between the
subjective and objective motility. There was also a significant difference in
motility depending on how the semen was handled (temperature and selection
through colloid centrifugation). The results indicated that the motility was best
preserved by selection and storage at + 5 ° C. There were also individual
differences between stallions, concerning the time their spermatozoa kept their
motility. Analysing spermatozoa with an atypical motility before and after
centrifugation showed that this method effectively selected progressively moving
spermatozoa.
This study showed that QualispermTM could be a good complement to traditional
methods in the field in the future, but some further development of the machine
must first be done. There is still some subjectivness built in the method, since the
user chooses the spot for the analyze, and there is also a need for training before
using QualispermTM