The aim of the present study was to evaluate the effect of sperm selection by single‐layer centrifugation (SLC) performed before freezing on sperm quality after thawing of Fleckvieh bull semen. Ejaculates from 22 bulls were collected by artificial vagina and divided into two aliquots. One aliquot (control sample) was diluted with Steridyl^® and frozen over nitrogen vapour in a Digitcool freezer (IMV Technologies). Sperm from the second aliquot (SLC sample) was selected using the SLC technique with Bovicoll colloid and then frozen over nitrogen vapour in a Digitcool freezer. After thawing, both samples (control and SLC) were evaluated by computer‐aided sperm analysis (CASA; SCA 6.4 System; Microptic S.L) for sperm motility parameters. Integrity of the plasma membrane (viability), high mitochondrial membrane potential (HMMP) and acrosome integrity were assessed using a Guava® easyCyte flow cytometer (IMV Technologies). Morphological examination of spermatozoa was performed by Differential Interference Contrast microscopy (Leica DMi8). Morphological examination of live, immobilized spermatozoa was analysed under high magnification (≥6,600×). After thawing, the mean sperm viability of the control sample was 51.57%, compared to 40.37% for the SLC sample (p  < .01). HMMP was higher (p  < .01) in the control sample (40.37% versus 28.96%), and the mean of live spermatozoa with damaged acrosome was significantly higher (p  < .03) in the SLC sample (1.63% versus 1.95%). The mean percentage of motile spermatozoa was 80.17% in the control sample, compared to 75.14% in the SLC sample (p  < .0195), and rapid subpopulation reduced from 20.08% to 8.99% (p  < .0001) after SLC. Percentage of hyperactivated sperm decreased from 12.23% to 4.28% (p  < .0001) after SLC. Given the overall results, the sperm quality of thawed Fleckvieh bull semen was not improved when sperm were selected by SLC before freezing.

中文翻译：

---

Bovicoll单层离心能改善Fleckvieh公牛冷冻解冻精液的精子质量吗？

本研究的目的是评估冷冻前进行单层离心（SLC）选择精子对Fleckvieh公牛精液解冻后精子质量的影响。通过人工阴道收集来自22头公牛的射精，并分成两等份。一个等分试样（对照样品）与Steridyl稀释^®然后在Digitcool冰箱（IMV Technologies）中用氮气蒸气冷冻。使用带有Bovicoll胶体的SLC技术从第二个等分试样中选出精子（SLC样品），然后在Digitcool冷冻机中用氮气蒸气冷冻。解冻后，通过计算机辅助精子分析（CASA； SCA 6.4系统； Microptic SL）评估两个样品（对照和SLC）的精子活力参数。使用Guava®easyCyte流式细胞仪（IMV Technologies）评估了质膜的完整性（生存力），高线粒体膜电位（HMMP）和顶体完整性。精子的形态学检查通过微分干涉对比显微镜（Leica DMi8）进行。高倍率（≥6,600×）下分析了活的固定化精子的形态学检查。解冻后p  <.01）。 对照样品中的HMMP较高（p <.01）（40.37％对28.96％）， SLC样品中具有被破坏的顶体的活精子的平均值显着较高（p <.03）（1.63％对1.95％） 。对照样本中活动精子的平均百分比为80.17％，而SLC样本中为75.14％（p  <.0195），SLC后快速亚群从20.08％降至8.99％（p  <.0001）。 SLC后，超活化精子的百分比从12.23％降低至4.28％（p <.0001）。考虑到总体结果，当在冷冻前通过SLC选择精子时，解冻的Fleckvieh公牛精液的精子质量没有改善。