Abstract: In order to explore the effect of proanthocyanidins (PC) on goat semen freezing, PC were added to the 2% soybean lecithin (SL) based extender to the final concentration of 0, 10, 20, 40, 60 μg·mL-1 (SL0, SL1, SL2, SL3, SL4 groups) with 20% egg yolk as control (EY group). After freezing-thawing, sperm viability, motility, plasma membrane integrity, acrosome integrity, mitochondrial activity, antioxidant index and apoptotic state were detected. The results showed that the semen extender in the 40 μg·mL^-1 PC (SL3) had  higher sperm viability, motility, plasma membrane integrity, acrosome integrity and mitochondrial activity after thawing (58.49%, 53.45%, 50.46%, 55.37% and 55.16%, respectively) than the other PC-based  extender concentrations and EY group (P<0.05). The contents of superoxide dismutase （SOD） (224.87 U·mL^-1) and glutathione peroxidase (GSH-PX) (129.6 U·L^-1) of SL3 group were the highest, and the total caspase apoptotic rate (54.33%) and TUNEL apoptotic rate (41.36%) of SL3 group were the lowest, which were significantly different with EY and SL0 groups (P<0.05). When the concentration of PC increased to 60 μg·mL-1, the quality indexes of thawed semen were significantly decreased, and the toxicity of PC was found in the goat semen freezing. In conclusion, 40 μg·mL^-1 PC addition in the diluent could reduce sperm oxidative damage, decrease apoptotic level and improve sperm quality. This study improved the effect of animal-free diluents in the freezing of goat semen, and increased the biosecurity and application prospect of goat frozen semen.

Key words: goat, semen freezing, soybean lecithin, proanthocyanidins, antioxidant

摘要： 为研究大豆卵磷脂稀释液中添加原花青素（proanthocyanidin，PC）对山羊精子的冷冻保护作用，以20％卵黄为对照（EY组），分别在大豆卵磷脂为基础稀释液的冻精稀释液中添加最终浓度为0、10、20、40、60 μg·mL-1的PC（分别命名为SL0、SL1、SL2、SL3、SL4组），冷冻-解冻后分别对精子活率、活力、质膜完整率、顶体完整率、线粒体活性、抗氧化和凋亡指标进行检测。结果表明，当大豆卵磷脂稀释液中PC添加浓度为40 μg·mL-1（SL3组）时，解冻后精子活力、活率、质膜完整率、顶体完整率和线粒体活性最高，分别达58.49%、53.45%、50.46%、55.37%和55.16%，显著高于其他PC添加组和EY组（P<0.05）。SL3组解冻后精子的超氧化物歧化酶（SOD）（224.87 U·mL^-1）和谷胱甘肽过氧化物酶（GSH-PX）含量（129.6 U·L^-1）最高，总caspase凋亡率（54.33%）和TUNEL凋亡率（41.36%）最低，与EY和SL0组差异显著（P<0.05）。当PC的添加浓度提高至60 μg·mL^-1（SL4组）时，解冻后精子质量显著下降，表现为对精子毒性作用。综上，在山羊精液冷冻中，大豆卵磷脂稀释液中添加PC浓度为40 μg·mL^-1可降低精子氧化损伤和细胞凋亡，提高冻精品质。该研究改善了无动物源稀释液在山羊精液冷冻中的应用效果，提高了山羊冻精的生物安全性和应用前景

关键词: 山羊, 精液冷冻, 大豆卵磷脂, 原花青素, 抗氧化