Department of Veterinary Clinical Medicine, College Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL.
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA.
J Equine Vet Sci. 2020 Apr;87:102910. doi: 10.1016/j.jevs.2020.102910. Epub 2020 Jan 7.
Urospermia is a major ejaculatory dysfunction affecting stallions. It has been thought that urine-contaminated semen should not be cryopreserved; however, on select cases, urine contamination of semen cannot be avoided. A recent study suggested that urospermic semen can be cryopreserved after cushion centrifugation and extension. Thus, this study aimed to assess the use of single-layer colloid centrifugation (SLC) to process frozen-thawed urine-contaminated stallion semen. Raw ejaculates (n = 55) from eight stallions were split into three groups: no urine, low (20%), or high (50%) urine contamination. Semen was extended 1:1, cushion-centrifuged, and resuspended at 200 million sperm/mL in BotuCrio. Resuspended semen was loaded in 0.5 mL straws and cryopreserved in liquid nitrogen. Samples were thawed (37°C for 30 seconds) and processed by SLC (400 g/30 minutes). Percentages of total motility (TM) and progressive motility (PM) were assessed with computer-assisted semen analyzer. Sperm viability (%VIAB) and yield were assessed with a NucleoCounter before and after gradient centrifugation. Data were analyzed with two-way ANOVA and Tukey's test. The motility parameters TM before SLC (control: 35 ± 2; low: 33 ± 0.7; high: 22 ± 1.8) after SLC (control: 51 ± 3.6; low: 42 ± 2.2; high: 25 ± 2.8) and PM before SLC (control: 24 ± 1.8; low: 21 ± 1.14; high: 12 ± 1.5) and after SLC (control: 40.3 ± 3.2; low: 31 ± 3.9; high: 14 ± 2) significantly decreased with increasing urine contamination. Urine contamination marginally reduced (P < .05) sperm viability after cryopreservation before SLC (control: 45 ± 0.7; low: 27 ± 0.2; high: 27 ± 0.3) and after SLC (control: 54 ± 0.5; low: 49 ± 0.7; high: 38 ± 0.6). Recovery rates of sperm after centrifugation were not significantly different between groups. In conclusion, urine contamination affects sperm motility parameters in a dose-dependent manner. Post-thaw SLC selected sperm with higher motility and viability in control and low groups but only selected sperm with higher viability in the high group.
尿精液症是一种影响种马的主要射精功能障碍。人们一直认为，尿液污染的精液不应进行冷冻保存；然而，在某些特定情况下，精液被尿液污染是无法避免的。最近的一项研究表明，经过缓冲离心和延伸处理后，尿液污染的精液可以进行冷冻保存。因此，本研究旨在评估使用单层胶体离心（SLC）处理冷冻-解冻的尿液污染的种马精液。从 8 匹种马采集的原始精液（n=55）分为三组：无尿液、低（20%）或高（50%）尿液污染。精液以 1:1 的比例进行延伸，缓冲离心，在 BotuCrio 中以 2 亿个精子/mL 的浓度重新悬浮。重新悬浮的精液装入 0.5 mL straws 中，并在液氮中冷冻保存。样品在 37°C 下解冻 30 秒，然后通过 SLC（400 g/30 分钟）处理。使用计算机辅助精液分析器评估总运动力（TM）和前向运动力（PM）的百分比。用 NucleoCounter 在梯度离心前后评估精子活力（%VIAB）和产量。使用双因素方差分析和 Tukey 检验进行数据分析。SLC 前的运动参数 TM（对照：35 ± 2；低：33 ± 0.7；高：22 ± 1.8）和 SLC 后的 TM（对照：51 ± 3.6；低：42 ± 2.2；高：25 ± 2.8）以及 SLC 前的 PM（对照：24 ± 1.8；低：21 ± 1.14；高：12 ± 1.5）和 SLC 后的 PM（对照：40.3 ± 3.2；低：31 ± 3.9；高：14 ± 2）随着尿液污染的增加而显著降低。尿液污染轻微降低了冷冻保存后精子活力（SLC 前：对照：45 ± 0.7；低：27 ± 0.2；高：27 ± 0.3）和 SLC 后的精子活力（对照：54 ± 0.5；低：49 ± 0.7；高：38 ± 0.6）（P<.05）。离心后各组精子回收率无显著差异。总之，尿液污染以剂量依赖的方式影响精子运动参数。解冻后 SLC 选择了对照组和低组中具有更高运动力和活力的精子，但仅在高组中选择了具有更高活力的精子。
