Relationship between subjective assessment of ram semen wave motion and objective assessment by optical flow and beads motion

The optical flow entropy (OFENT) and the optical flow entropy autocorrelation (AUTO) showed a negative nonlinear relation with the wave motion score (WMS) over the 1-5 range (Fig. 3). The average (AVG) and standard deviation of the average speed (STD) parameters describing the speed of the beads showed a positive nonlinear relation with the wave motion score over the 1-5 range (Fig. 4). AVG and STD were significantly higher when the wave motion score was&gt; 4. Cohen's kappa coefficient was calculated to assess the concordance of the ejaculate selection based on the AVG, STD and OFENT parameters or the subjective wave motion score. The thresholds values for AVG, STD and OFENT were, respectively, 1, 0.7 and -2 and gave similar kappa values of 0.49, 0.50 and 0.45 respectively. Regarding the accuracy of detection of bad quality ejaculates and the ability to discard semen with potentially low fertility, the AVG parameter showed the highest sensitivity and specificity with values of 88 % and 77 % respectively. <br>