Ampullar and Ductus Deferens Aspiration Increases the Total Number of Viable Spermatozoa Recovered from Stallion Extragonadal Sperm Reserves

Abstract

Background: Equine spermatozoa acquire maturation and fertilization capacity during their passage from the testis towards the cauda epididymis and are concurrently stored in the cauda epididymis and ampullae of the ductus deferens. In case of sudden death or emergency castration, epididymal spermatozoa can be harvested and successfully preserved. Ampullar aspiration was not previously described, even though the ampullae of the ductus deferens and the ductus deferens are valuable sources of mature spermatozoa in equines. The aim of this study was to describe a technique to collect spermatozoa from the ampullae of the ductus deferens and the ductus deferens of stallions during routine castration and to compare kinematic parameters of these spermatozoa to spermatozoa harvested from the cauda epididymis of the same stallion. Methods: Fourteen ampullae of the ductus deferens were successfully aspirated during the routine castration of 10 stallions, followed by epididymal sperm harvest. Concentration and motility parameters were assessed, computer-assisted and were compared to epididymal spermatozoa. Result: Ampullar and ductus deferens spermatozoa increased the total number of spermatozoa recovered by approximately 6%. Progressive motility (PM), velocity of the average path (VAP), velocity of the curved line (VCL) and linearity (LIN) did not differ significantly (P≤0.05) between the ampullar spermatozoa (AS) and the epididymal spermatozoa (ES). Total motility (TM) was significantly lower (P= 0.04) in the AS group.