Re-assessing different thawing temperatures in bull semen doses | Reevaluando diferentes temperaturas de descongelación en dosis de semen bovino
2011
Muiño, R., Universidad de Santiago de Compostela, Lugo (España). Facultad de Veterinaria | Peña, A.I., Universidad de Santiago de Compostela, Lugo (España). Facultad de Veterinaria
The aim of this study was to evaluate three thawing rates for bull semen frozen in 0.25 ml-straws: placing straws in a water bath at 35 deg C for 40 s, at 50 deg C for 15 s or at 70 deg C for 5 s. In a first experiment, the 3 thawing rates were compared in relation to post-thaw sperm motility determined subjectively, and sperm plasma and acrosomal membrane integrity were examined by flow cytometry after 0 and 5 h of incubation at 37 deg C. In a second experiment, the three thawing rates were evaluated based on post-thaw sperm motility, determined using a CASA system, after 0 and 2 h of incubation at 37 deg C. Then, the individual motility descriptors were analysed using a multivariate clustering procedure to test the presence of separate sperm subpopulations with specific motility characteristics. There were no significant differences between the 3 thawing methods on post-thaw motility or plasma and acrosomal sperm membrane integrity. The thawing rate had no significant influence on the frequency distribution of spermatozoa within the 4 subpopulations, but higher proportions of spermatozoa with fast and progressive movement were observed after post-thaw incubation when faster thawing rates were used.
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