This study examines the effect of L‐carnitine (LC) on chilled ram semen stored for up to 96 hr. Semen samples were collected, placed in a skimmed milk + 6% egg yolk extender, pooled, aliquoted and diluted with the same extender supplemented with different LC concentration: 0 (control), 1 mM (LC1), 2.5 mM (LC2.5), 5 mM (LC5), 7.5 mM (LC7.5) or10 mM (LC10). Sperm kinetics and membranes (plasma, acrosome and mitochondrial) were examined using the CASA system and triple fluorescence staining (PI/ PNA‐FITC/Mitotracker). The progressive motility was greater (p  < .05) with LC7.5 treatment than the control sperm at 96 hr. The curvilinear velocity (p  < .01) and the percentage of sperm with intact membranes (plasma/acrosome/mitochondria) (p < .01) were greater with all LC treatments than the control group at all times. Straight line velocity was greater (p < .01) with LC5 and LC7.5 treatments than the control group after 48 hr. The LC5 group also returned lower ALH values (p < .05) than these seen for the control groups after 48 hr. The fertilizing capacity of LC5 samples stored at 15°C for 2 hr (LC5‐15°C‐2h) and at 5°C for 24 hr (LC5‐5°C‐24h) was tested in three ewe groups via cervical fixed‐time artificial insemination. In two groups, the fertilizing capacity of the LC5‐5°C‐24h was reduced (p  < .001). In the remaining group, however, no significant difference was seen between the LC5‐15°C‐2h and LC5‐5°C‐24h sperm in this respect (pregnancy rates 52.4% versus 42.8%; p  > .05). Overall, the present results suggest that supplementing skimmed milk–egg yolk‐based extenders with LC has a positive effect on chilled sperm variables and fertilizing capacity.

中文翻译：

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向脱脂的乳蛋黄蛋黄补充剂中补充左旋肉碱有助于维持冷冻公羊精子的活力，膜完整性和受精能力。

这项研究检查了左旋肉碱（LC）对冷藏达96小时的冷冻精液的影响。收集精液样品，放入脱脂牛奶+ 6％蛋黄增量剂中，合并，等分并用相同的增量剂稀释，并补充不同的LC浓度：0（对照），1 mM（LC1），2.5 mM（LC2.5） ，5 mM（LC5），7.5 mM（LC7.5）或10 mM（LC10）。使用CASA系统和三重荧光染色（PI / PNA-FITC / Mitotracker）检查了精子动力学和膜（血浆，顶体和线粒体）。 用LC7.5处理的进行性运动能力在96小时时大于对照精子（p <.05）。曲线速度（p  <.01）和具有完整膜的精子百分比（血浆/顶体/线粒体）（p <.01）在所有时候，所有LC治疗均大于对照组。LC5和LC7.5处理的直线速度在48小时后大于对照组（p < 0.01）。LC5组在48小时后还返回了比对照组低的ALH值（p < .05）。在三个母羊组中，通过宫颈固定测试了在15°C下储存2小时（LC5-15°C-2h）和在5°C下储存24小时（LC5-5°C-24h）的LC5样品的受精能力。时间人工授精。在两组中，LC5-5°C-24h的施肥能力降低了（p  <.001）。然而，在其余组中，LC5-15°C-2h和LC5-5°C-24h精子在这方面没有显着差异（妊娠率分别为52.4％和42.8％；p > .05）。总体而言，目前的结果表明，补充LC脱脂牛奶蛋黄基补充剂对冷冻精子变量和受精能力具有积极作用。