The response of ram spermatozoa to preparations of egg yolk in semen diluents during storage at 5 or?196°C

Abstract

Egg yolk dispersed at levels between 0.1 and 3.75% (v/v) in a diluent used for the preservation of ram spermatozoa at 5±C was shown to affect the structure and survival of spermatozoa. A motility-preserving factor was studied in greater detail but a factor causing disruption of the acrosome was also detected. The substance prolonging the motile life of spermatozoa was shown to be a regular component of hen eggs, it was stable during storage of the egg up to 28 days after laying, and heating of the yolk-containing diluent to 100±C for 30 min inactivated it. After centrifugation of the yolk-containing diluent at 35, 000 g for 30 min, the motility-preserving factor remained in the supernatant solution. More than 50% of spermatozoa survived for 72 hr at 5±C when the supernatant solution contained 15 mg/ml of soluble egg yolk solids, in contrast with a survival of less than 20% when egg yolk was not included in the diluent. © 1973, CSIRO. All rights reserved.