The effect of pH and viscosity on bovine spermatozoa motility under controlled conditions.

Infertility in a large proportion of infertile couples is due, in part, to the male factor. Spermatozoa must survive the unique environment of the female reproductive tract in their path to fertilize the ovum. This fact is even more problematic for men with oligospermia. Of the many environmental factors that effect sperm motility in the female reproductive tract, we have decided to concentrate on the effect of pH and viscosity on bovine spermatozoa in the laboratory setting. Follicular fluid was harvested from heifer ovaries to serve as a chemo-attractant. Through image analysis, our data shows trends of sperm motility as a function of pH and viscosity. There is a significant increase in the number of immotile sperm seen as pH decreases from 6.5 to 6.0. Furthermore, an exponential relationship between sperm speed and environmental viscosity was observed in vitro. This suggests that modulating vaginal pH and vaginal secretion viscosity could greatly affect spermatozoa motility and therefore male fertility.