Effect of post-mortem and storage on quality of epididymal sperm in Taleshi ram testis

This research was carried out to study the effect of time interval between animal death and sperm recovery (24 or 48 h) on the quality of ram spermatozoa from cauda epididymis. The effectof two storage temperatures (room temperature or 5 0C) was analyzed. Testicles from 24 Taleshi rams (approximately 3-5 years old and BW 61±5.5 kg) were collected from slaughterhouse. One testicle from each pair was stored at room temperature (RT) (20 0C) and semen collection was carried out in the first 2 h after slaughter (control group). The other testicles were divided into four groups: kept at RT for 24 h, at 5 0C for 24 h, at RT for 48 h and at 5 0C for 48 h. Sperms were obtained by slicing the tissue of the cauda epididymis with a scalpel and then, sperm concentration was determined. Spermatozoa were diluted with Tes- Tris-Fructose solution supplemented with egg yolk and glycerol. The percentage of total motility and progressive motility, functional integrity of the sperm plasma membrane, spermviability and pH were measured. The results indicated that total motility, progressive motility, viability and functional integrity were significantly different between groups (p<0.05). pH was decreased with prolongation of postmortem time but was not statistically different (p>0.05). Sperms collected from the testis which were kept at 5 0C, showed better quality. The sperms belong to the testis kept up to 24 h showed better quality than those kept for 48 h. In conclusion, a good protocol for post-mortem semen collection in rams when epididymal spermatozoa can not be collected immediately is to preserve the epididymis at 5 0C and process the samples in the first 24 h after the death.