COMPUTER-ASSISTED ANALYSIS OF MOTILITY, VELOCITY AND LINEARITY OF DOGSPERMATOZOA

Two different computer systems were tested for the analysis of motilit y parameters of dog semen. First, the Cellsoft computer videomicrograp hy system was adapted to the morphological and motility traits of dog semen. The computer-calculated motility (percentage of progressively m otile spermatozoa) was significantly correlated with the estimated mot ility (r = 0.97, P < 0.001), as was the sperm concentration determined by counting chamber and by computer (r = 0.62, P < 0.001). Mean veloc ity varied from 61-1 to 102.1 mum s-1. Irrespective of a low or high m otility, the linearity varied from 5.9 +/- 3.5 to 7.6 +/- 0.9. Second, in an investigation into suitability of different concentrations (4, 6 and 8%) of glycerol for freezing dog semen diluted with a Tris-egg-y olk extender, the Stromberg-Mika Cell Motion Analyser was used. Partic les identified as spermatozoa ranged in size from 35 to 350 pixels. Th e mean computer-calculated motility was 93.1 +/- 2.9% in the diluted s emen without glycerol; 10 min after adding glycerol it was 88.0 +/- 3. 8% with 4% glycerol, 83.7 +/- 4-9% with 6% glycerol, and 78.6 +/- 6.3% with 8% glycerol. Significant correlations were found between the est imated and the computer-analysed motility for the fresh diluted semen (P < 0.01) and for the thawed semen, irrespective of the glycerol conc entration (P < 0.001). The mean velocity was 159.3 +/- 13.8 mum s-1 be fore adding glycerol, showing a decreasing tendency thereafter. Genera lly, linearity varied from 66 +/- 6% to 79 +/- 4%. Computer-assisted s emen analysis in experiments on semen preservation appears to be usefu l, as it offers additional parameters for the characterization and eva luation of spermatozoal motion dynamics.