Cryopreservation of epididymal bovine spermatozoa from dead animals and its uses in vitro embryo production

The present study aimed to evaluate viability and in vitro fertilizing ability of cryopreserved epididymal spermatozoa obtained from dead animals. To collect spermatozoa, epididymides from three males (Bulls A1, A2 and A3) were collected at a local slaughterhouse. As a reference ejaculate from a bull with known in vitro fertility, was used. Sperm characteristics (motility, chromatin and acrosome integrity) were evaluated before and after cryopreservation. Then, frozen spermatozoa from all animals were used for in vitro fertilization. Cleavage and blastocyst rates at 48 h (day 2) and 168 h (day 7) post in vitro insemination, for bull A1 (82.1 and 38.6%) and A2 (80.7 and 33.8%) were similar (P > 0.05) to the reference bull (88.9 and 57.2%). Bull A3 had the lesser cleavage (42.0%) and blastocyst (26.1%) rates. The results showed that epididymal spermatozoa from dead animals can be successfully cryopreserved and used in vitro production of embryos.