Abstract: | Washed fowl spermatozoa were incubated in a phosphate buffer containing various concentrations of fowl seminal plasma at 41 degrees C, normal body temperature, and the motility and oxygen consumption of spermatozoa were determined. Immediately after the incubation, spermatozoa showed good motility in the various diluents. However, with concentrations of seminal plasma at or below 20%, spermatozoa quickly became immotile. In contrast, at concentrations higher than 40% seminal plasma, spermatozoa were motile even after 15 min. As the concentration of seminal plasma was increased, oxygen consumption of spermatozoa also increased. A filtrate of the seminal plasma, obtained by passing the fluid through an Amicon YM-2 ultra-filtration membrane (Mr less than 1000), also stimulated the motility and oxygen consumption of spermatozoa. These results suggest that some low molecular weight factor(s) in fowl seminal plasma stimulated motility and oxygen consumption of fowl spermatozoa at 41 degrees C. A physiological role of this factor(s) may be to assist passage of spermatozoa through the vagina after natural mating. |