THE INFLUENCE OF THE AGEING OF RABBIT SPERMATOZOA <i>IN VITRO</i> ON FERTILIZING CAPACITY AND EMBRYONIC MORTALITY

Abstract

Summary. Female rabbits were inseminated with spermatozoa which had either been freshly ejaculated or stored for 24 or 48 hr at 5° C. One oviduct of each female was flushed 26 to 28 hr after insemination and hcg injection. The ova were examined and returned to the same oviduct if cleavage had occurred. This procedure did not affect the subsequent development of the ova, as compared with those in the undisturbed oviduct. The number of implantations was counted at 8 days and the number of live foetuses at 20 days of pregnancy. Compared with fresh spermatozoa, the stored samples showed significantly lower fertilizing capacity and the fertilized ova showed significantly higher pre- and postimplantation losses.