Bovine frozen semen motility analysis using two different laser wavelengths

Abstract

Laser of 632 and 532 nanometers were evaluated for bovine semen kinetic analysis. Numerical index of dynamic laser speckle (DLSI) was compared with motility assessment by light microscopy. Straws (n = 123) were thawed and evaluated as to velocity and cell motility. In assay one, each sample was lit by either kind of laser (red, n = 56; green, n = 20). In the second assay 46 samples were lit alternately by both laser sources. An index grouping velocity and motility was used to compare the evaluations. In a third assay a single sample was illuminated with both laser sources to assess the motility decreasing, and regression analysis of dynamic laser speckle index, velocity and motility index have been done. Correlations between dynamic laser speckle index, velocity and cell motility were r = 0.594; r = 0.734 and r = 0.665; r = 0.684 for samples illuminated by red and green laser, respectively. Correlation coefficients for red and green laser found between DLSI index and velocity (r = 0.801; r = 0.590), cell motility (r = 0.826; r = 0.613) and velocity and motility index (r = 0.840; r = 0.618), were significant (p < 0.01). No difference was observed between the laser sources that were sensitive in detecting semen activity, thus both of them can be used to generate the biospeckle phenomena and assess motility in the bull frozen semen.