Decay of sperm obtained from epididymes of wild ruminants depending on postmortem time

Abstract

We have carried out a study on the effect of postmortem time (PT) in some characteristics of epididymal sperm salvaged from hunted Iberian red deer and roe deer. Testis were collected, identified, refrigerated down to 5 degrees C, and sent to our laboratory by the wardens of the hunting reserves. This way, samples were delivered at different times postmortem. Sperm were extracted from the cauda epididymis by means of cuts. Analyzed parameters were: osmolality, pH, motility-both subjectively and with CASA, HOS test reactivity, acrosomal status and viability (assessed with propidium iodide). Osmolality and pH rose with prolonged postmortem time, possibly due to tissue decomposition. Most sperm quality parameters negatively correlated with PT. Besides, when comparing PT classes (groups of 24 h for red deer and 30 h for roe deer), we could appreciate that motility was more affected by PT than other quality variables. Progressive motility was especially impaired. We also classified the samples in high, medium and low quality for each PT group (considering progressive motility, intact acrosomes and reactivity to the HOS test), and it was clear that after 2 days the number of high quality samples was testimonial, and after several days, we almost found only low quality samples. In conclusion, epididymal sperm from Iberian red deer and roe deer undergo a decrease of quality with PT, but it could stay acceptable within many hours postmortem. There are implications for wildlife conservation programs, as epididymal sperm is a good source of germplasm. If valuable animals die and it is not possible to process their sperm immediately, it may still be possible to obtain viable spermatozoa many hours later.

Morphological defects of epididymal spermatozoa in male roe deer (Capreolus capreolus) during the reproductive season

“…A viable alternative to these methods is the postmortem recovery of spermatozoa during the hunting season. It has been proven that semen from wild ruminants, including roe deer, that is kept at low temperatures (5 o C) in the epididymis postmortem and is subsequently obtained from the cauda epididymis, maintains good quality for a long time after the death of the animal (Martinez-Pastor et al 2005a, Martinez-Pastor et al 2005b. The effect of season on epididymal spermatozoa recovered postmortem has also been investigated.…”

Nascimento de bezerros normais após inseminação artificial utilizando espermatozóides criopreservados obtidos de epidídimos refrigerados de bovinos após a morte

“…armazenamento no epidídimo após a morte tem sido demonstrado em várias pesquisas com diferentes espécies (FERNÁNDEZ-SANTOS et., 2009, MARTINEZ-PASTOR et al, 2005, KAABI et al, 2003. Em seu estudo com Capra pyrenaica hispânica, SANTIAGO-MORENO et al (2007) constataram que a queda na qualidade dos espermatozóides está primariamente correlacionada com a queda da motilidade, sendo este o principal parâmetro afetado.…”

Viability of ovine spermatozoa collected from epididymides stored at 18°-25°C for 48 hours post mortem

“…This depreciation is a result of spermatozoa aging and epididymides tissue degeneration and decomposition process (Martinez-Pastor et al, 2005b). Studies in rats revealed that degenerative testicular changes start approximately six hours after death, but in the epididymis, these alterations only begin 12 hours after death (Songsasen et al, 1998).…”