POSTMORTEM ASSESSMENT OF SPERM CHARACTERISTICS OF THE RED DEER DURINGTHE BREEDING-SEASON

This study examined the effect of male age, time lapse between death o f individual and collection of its sperm, breeding season (1993, 1995, or 1996), and testicle sampled (left or right) on the cell quality of spermatozoa obtained postmortem from the epididymis of red deer stags (Cervus elaphus hispanicus). A total of 142 sperm samples obtained fr om 71 free-ranging individuals shot during the breeding season were us ed to investigate these effects. The spermatozoa were obtained from th e cauda epididymis of stags. Immediately after collection, an assessme nt was made of the proportion of motile spermatozoa (PM), normal morph ology (PN), intact acrosomes (PIA), and the osmotic resistance degree of the plasmatic spermatozoa membrane as determined by the cell endosm osis test (E+). Gamete quality was influenced by both the age of the i ndividuals and the lapse between death and collection of sperm (p < 0. 001), whereas the year of collection and testicle sampled did not affe ct sperm quality. Sperm samples were classified in three groups: excel lent, acceptable, or unacceptable, depending on the values achieved in the PM, PN, E+, and PIA variables. Acceptable samples had to achieve the following score: PM > 40%, PN > 40%, E+ > 40%, and PIA > 60%. With in this group, samples with a PM > 60% were classified as excellent. T he percentage of samples classified as viable (strictly acceptable plu s excellent) achieved 59.8% (85 out of 142). These results indicate th at it is possible to obtain a remarkable percentage of viable sperm af ter the death of the deer. This finding might also be useful to obtain embryos of threatened species of wild ungulates.