High-throughput characterisation of bull semen motility using differential dynamic microscopy

We report a high-throughput technique for characterising the motility of spermatozoa using differential dynamic microscopy. A movie with large field of view (∼10mm(2)) records thousands of cells (e.g. ≈ 5000 cells even at a low cell density of 20 × 10(6) cells/ml) at once and yields averaged measurements of the mean ([Image: see text] ) and standard deviation (σ) of the swimming speed, head oscillation amplitude (A(0)) and frequency (f(0)), and the fraction of motile spermatozoa (α). Interestingly, we found that the measurement of α is facilitated because the swimming spermatozoa enhance the motion of the non-swimming population. We demonstrate the ease and rapidity of our method by performing on-farm characterisation of bull spermatozoa motility, and validate the technique by comparing laboratory measurements with tracking. Our results confirm the long-standing theoretical prediction that [Image: see text] for swimming spermatozoa.