Swanson W F, Bateman H L, Vansandt L M
Cincinnati Zoo & Botanical Garden, Center for Conservation and Research of Endangered Wildlife, 3400 Vine Street, Cincinnati OH USA.
Reprod Domest Anim. 2017 Apr;52 Suppl 2:255-260. doi: 10.1111/rda.12863. Epub 2016 Nov 3.
Semen banking of domestic cats and wild felids represents a vital resource for their long-term conservation, but current methods require access to advanced training and specialized equipment. A newer method of semen collection, urethral catheterization of medetomidine-treated cats, allows recovery of high sperm numbers, but it is unclear if this approach permits maximal sperm recovery or is feasible using less expensive alpha-2 agonists. Similarly, a newer sperm preservation approach, vitrification, offers advantages of simplicity and minimal equipment needs, but its efficacy in combination with urethral catheterization has not been investigated. Our specific objectives were to (i) evaluate sequential semen recovery with urethral catheterization and electroejaculation in domestic cats, (ii) assess the effectiveness of a weak (xylazine) versus strong (dexmedetomidine) alpha-2 agonist for inducing sperm release, and (iii) compare post-thaw sperm motility, acrosome status and fertilizing capacity of catheter-recovered samples after vitrification or straw freezing. Results indicated that electroejaculation following repeated catheterization allowed recovery of additional spermatozoa (range, 11-32 × 10 sperm/male) and that xylazine was ineffective for inducing meaningful sperm release (range, 0-0.4 × 10 sperm/male). Post-thaw motility and acrosome status of vitrified catheter samples did not differ (p > .05) from that of straw frozen samples. Preliminary results indicated that in vitro fertilization success (9/30, 30%) of vitrified catheter sperm did not differ (p > .05) from that observed with straw frozen samples (17/30, 57%). In conclusion, urethral catheterization of dexmedetomidine-treated cats allows recovery of substantial sperm numbers but electroejaculation still may be warranted for maximal sperm recovery. Xylazine is not suitable as an inexpensive alternative to dexmedetomidine for catheterization. Vitrification of catheter samples results in comparable post-thaw parameters to straw freezing and may be adequate for use with oviductal insemination procedures.
家猫和野生猫科动物的精液保存是其长期保护的重要资源，但目前的方法需要经过高级培训并使用专门设备。一种新的精液采集方法，即对用美托咪定治疗的猫进行尿道插管，可采集到大量精子，但尚不清楚这种方法是否能实现最大程度的精子采集，或者使用成本较低的α-2激动剂是否可行。同样，一种新的精子保存方法——玻璃化，具有操作简单和设备需求最少的优点，但其与尿道插管联合使用的效果尚未得到研究。我们的具体目标是：（i）评估在家猫中通过尿道插管和电射精顺序采集精液的情况；（ii）评估弱效（赛拉嗪）与强效（右美托咪定）α-2激动剂诱导精子释放的有效性；（iii）比较玻璃化或细管冷冻后经导管采集样本的解冻后精子活力、顶体状态和受精能力。结果表明，在重复插管后进行电射精可采集到更多精子（范围为11 - 32×10⁶精子/雄性），且赛拉嗪诱导有意义精子释放的效果不佳（范围为0 - 0.4×10⁶精子/雄性）。玻璃化导管样本解冻后的活力和顶体状态与细管冷冻样本相比无差异（p > 0.05）。初步结果表明，玻璃化导管精子的体外受精成功率（9/30，30%）与细管冷冻样本（17/30，57%）相比无差异（p > 0.05）。总之，对用右美托咪定治疗的猫进行尿道插管可采集到大量精子，但为实现最大程度的精子采集，电射精可能仍有必要。赛拉嗪不适合作为右美托咪定用于插管的廉价替代品。导管样本的玻璃化导致解冻后参数与细管冷冻相当，可能足以用于输卵管授精程序。
