The investigation of an effective diluent for the cryopreservation of rabbit semen (#503)
The
successful cryopreservation of rabbit semen requires the assembly of a diluent
with effective permeable and non-permeable cryoprotectants which are correctly
quantified. The aim of this study was to evaluate the effects of various
dimethyl sulfoxide (DMSO) and sugar concentrations on rabbit spermatozoa during
the cryopreservation processes. Four ejaculates from three mature male rabbits
(n = 12) were diluted with one of
three Tris-based diluents composed of 313.79 mM Tris, 103.07 mM citric acid.H2O,
50 mM glucose, 80 mg/L kanamcyin and 17%
egg yolk plus 3.5%, 7% or 10% DMSO. Diluted samples were cooled to 5°C and frozen in straws using liquid nitrogen and
later thawed and kept at 37˚C. Sperm motility and kinetic parameters were
assessed using a Computer Assisted Sperm Analyser (CASA), while the integrity
of the sperm membrane, acrosome and DNA was calculated using fluorescent
staining and flow cytometry. Diluents with lower concentrations of DMSO (3.5%)
were shown to have greater cryoprotective effects on motility and kinetic
traits (P<0.001), however diluents with 7% and 10% DMSO resulted in significantly
higher percentages of sperm with intact membranes (P<0.001). Using 7% DMSO,
diluents were then supplemented with either 50 mM glucose, 50 mM sucrose or an amalgamation
of both. Diluents with glucose produced sperm with significantly greater post-thaw
motility and percentage of intact DNA (P<0.001), however cryopreservation
with sucrose produced a significantly higher percentage of sperm with intact
acrosomes (P<0.001). Overall, the use of 7% DMSO and low concentrations of
sugars in the diluent (50 mM) produced greater post-thaw motility and intact
DNA; but diluents with higher sugar concentrations (100 mM) produced
significantly higher percentages of sperm with intact acrosomes after cryopreservation.
These findings allow for further investigation into the development of an
effective media for the cryopreservation and transportation of rabbit semen
throughout the farming industry.