Arnold Danielle M, Gray Charlie, Roth Terri L, Mitchell Sebastian, Graham Laura H
Department of Animal Biosciences, University of Guelph, 50 Stone Rd., E, Guelph, Ontario, N1G 2W1, Canada.
African Lion Safari, Cooper Rd., Cambridge, Ontario, N1R 5S2, Canada.
Anim Reprod Sci. 2017 Jul;182:84-94. doi: 10.1016/j.anireprosci.2017.05.003. Epub 2017 May 18.
The specific objectives of the present study were to investigate the effects of manual seeding, differing freeze and thaw rates as well as storage for 24h at 4°C prior to cryopreservation on post-thaw sperm quality in Asian elephants. Extended semen was cooled in an equitainer to 4°C, frozen in liquid nitrogen vapour at various rates with and without manual seeding or in a dry shipper and thawed at 37, 50 and 75°C. There was a significant effect of freeze rate on post-thaw motility (P<0.0001) and acrosomal integrity (P<0.005). The faster freeze rates in the dry shipper and at 1cm or 2cm above liquid nitrogen consistently provided better cryopreservation than slower freezing rates. Thaw temperature had no effect on post-thaw semen quality but there was an interaction between freeze and thaw rates with higher thaw rates resulting in superior post-thaw semen quality in straws frozen at fast rates. Storage of samples prior to freezing had a detrimental effect on post-thaw semen quality. In summary, our results indicate cooling extended semen in an equitainer and cryopreserving it by placing straws directly in a dry shipper is a simple technique for effectively cryopreserving Asian elephant semen in the field or zoo.
本研究的具体目标是调查人工播种、不同的冻融速率以及在冷冻保存前于4°C下储存24小时对亚洲象冻融后精子质量的影响。将稀释后的精液在平衡仪中冷却至4°C，在液氮蒸气中以不同速率进行冷冻，有或没有人工播种，或在干式运输箱中冷冻，并在37°C、50°C和75°C下解冻。冷冻速率对冻融后的活力（P<0.0001）和顶体完整性（P<0.005）有显著影响。在干式运输箱中以及在液氮上方1厘米或2厘米处的较快冷冻速率始终比缓慢冷冻速率提供更好的冷冻保存效果。解冻温度对冻融后的精液质量没有影响，但冷冻速率和解冻速率之间存在相互作用，较高的解冻速率会使快速冷冻的细管中冻融后的精液质量更好。冷冻前样品的储存对冻融后的精液质量有不利影响。总之，我们的结果表明，在平衡仪中冷却稀释后的精液并通过将细管直接放入干式运输箱中进行冷冻保存是一种在野外或动物园有效冷冻保存亚洲象精液的简单技术。
