Recovery and Cryopreservation of Epididymal Sperm of Plains Bison (Bison bison bison) as a Model for Salvaging the Genetics of Wood Bison (Bison bison athabascae)

• Published in: Reproduction in domestic animals 2009-10, Vol.44 (5), p.815-822
• Main Authors: Aurini, LC, Whiteside, DP, Elkin, BT, Thundathil, JC
• Format: Article
• Language: English
• Subjects: Acrosome - ultrastructure; Animals; Biological and medical sciences; Bison; Bison bison bison; Buffalo; Conservation of Natural Resources; Cryogenic engineering; Cryopreservation - methods; Cryopreservation - veterinary; Embryo Culture Techniques - veterinary; Embryonic Development; Endangered Species; Epididymis - cytology; Fertilization in Vitro - veterinary; Fundamental and applied biological sciences. Psychology; Hot Temperature; Male; Males; Mammalian reproduction. General aspects; Reproductive technologies; Semen Preservation - methods; Semen Preservation - veterinary; Solutions; Sperm Count; Sperm Motility; Spermatozoa - physiology; Spermatozoa - ultrastructure; Tissue and Organ Harvesting - methods; Tissue and Organ Harvesting - veterinary; Vertebrates: reproduction; Veterinary medicine
• ISSN: 0936-6768; 1439-0531
• DOI: 10.1111/j.1439-0531.2008.01087.x

The objective of this study was to optimize recovery and cryopreservation of epididymal sperm from plains bison, as a model for wood bison. In Phase 1, cauda epididymides were recovered from bison (n = 14) immediately after slaughter, minced and incubated in Sp-TALPH buffer for 3 h at 36°C. The resulting sperm suspensions were cryopreserved in Triladyl®, using a protocol for bovine semen. In Phase 2, epididymal sperm were cryopreserved in either Triladyl® or Andromed®. The mean (±SD) estimated number of sperm recovered was 468 ± 207 x 10⁶. There was an increase (p < 0.05) in the proportion of sperm with normal morphology between initial recovery and after extension (52.4 ± 4.6 vs 69.7 ± 2.4%), with a concurrent decrease (p < 0.05) in the proportion of sperm with distal droplets. Median values for progressively motile sperm in post-thaw samples (60%) were lower (p < 0.05) than that after extension or after chilling (70% for both). The mean percentages of viable sperm and of sperm with an intact acrosome were lower (p < 0.05) for frozen-thawed samples (38.7 ± 2.8 and 85.2 ± 1.1) compared with extended (66.2 ± 2.2 and 92.4 ± 0.9) or chilled (63.7 ± 2.5 and 90.0 ± 1.0) samples. Rates of cleavage, morulae and blastocyst production were not significantly different for chilled (70.9, 38.7 and 8.0%) vs post-thaw sperm (73.0, 46.0 and 6.3%). There was no significant difference between extenders for most sperm characteristics. In conclusion, we developed a functional protocol for the recovery and cryopreservation of epididymal sperm from plains bison, which may have implications for the genetic preservation of wood bison.