Egg Yolk-Coagulating Enzyme in the Semen and Cowper's Gland of the Goat

Abstract

GLYCINE egg yolk and egg yolk citrate, prepared by mixing equal volumes of 4 per cent glycine and egg yolk and 3.6 per cent sodium citrate and egg yolk, were used in an attempt to extend the volume of ejaculated goat semen and to preserve the motility and fertility of the spermatozoa. With semen diluted twenty times it was found that most of the initially motile spermatozoa remained so for three days in both the diluents at 3° C. ; thereafter the number of live sperm and degree of motility declined precipitously. Extinction of spermatozoal life in glycine egg yolk was always preceded by coagulation of the diluent. The following observations show that this coagulation is due to the presence of an enzyme in goat semen. The enzyme is present in plasma and requires activation by calcium ; hence absence or delay of coagulation of medium containing citrate. Further, when spermatozoa are freed from this enzyme, by washing with normal saline, viability is greatly improved.