Computer-assisted analysis of motility, velocity and linearity of dog spermatozoa

Two different computer systems were tested for the analysis of motility parameters of dog semen. First, the Cellsoft computer videomicrography system was adapted to the morphological and motility traits of dog semen. The computer-calculated motility (percentage of progressively motile spermatozoa) was significantly correlated with the estimated motility (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 velocity varied from 61.1 to 102.0 microns s-1. Irrespective of a low or high motility, 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-yolk extender, the Strömberg-Mika Cell Motion Analyser was used. Particles identified as spermatozoa ranged in size from 35 to 350 pixels. The mean computer-calculated motility was 93.1 +/- 2.9% in the diluted semen 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 estimated and the computer-analysed motility for the fresh diluted semen (P < 0.01) and for the thawed semen, irrespective of the glycerol concentration (P < 0.001). The mean velocity was 159.3 +/- 13.8 microns s-1 before adding glycerol, showing a decreasing tendency thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)