A New Optical Technique for Evaluating Collective Motility of Ram and Bull Ejaculated Spermatozoa

A new. non‐destructive, objective technique for measuring collective motility of highly‐concentrated ram and bull semen is described. The principle is based on changes in the reflected light scattered by motile spermatozoa. These changes can be recorded as a continuous analog wave pattern (Reflectospermiogram‐RSG) and are correlated to the intensity of the turbulent motility as evaluated subjectively with an ordinary light microscope. Ram spermatozoa have, after ejaculation, a typical motility pattern, i.e., high, stable activity for about 20 min, then a period during which the motility decreases at a constant rate, and finally, a period with a low but rather constant activity. The usefulness of the technique has been demonstrated in various types of experiments.