Reversal of motility loss in bongo antelope (Tragelaphus eurycerus isaaci) spermatozoa contaminated with hyposmotic urine during electroejaculation

Semen collected by a combination of ampullary (rectal) massage and electroejaculation of a bongo bull was incidentally contaminated with urine (1:3.7). At 1.5 h post-collection, progressive motility was 0% but some spermatozoa had intermittently twitching tails. Subsequent dilution with media and processing improved the progressive motility (up to 50%) and intact membranes (up to 71%) of spermatozoa. After thawing, the respective values were 35 and 70%. The osmolarity and pH of the contaminated supernatant was 151 mOsm and 7.45, respectively. Initial progressive motility in a non-contaminated portion of semen collected during the same procedure was 80%, and, after thawing, 60 and 90%, of the spermatozoa showed progressive motility and intact membranes, respectively. In conclusion, urine-contaminated bongo spermatozoa can regain progressive motility after dilution with isosmotic solutions and survive cryopreservation.