Fish oil associated to ascorbic acid in diluter for cryopreservation goat semen

ABSTRACT The study aimed to evaluate the effect of fish oil inclusion associated with ascorbic acid in the thinner for goat semen cryopreservation. Two male Boers underwent semen collection through the artificial vagina method, ejaculates being then assessed for physical and morphological aspects. After evaluation, a pool was formed, followed by the split into five groups: G1 - yolk-citrate extender and G2, G3, G4 and G5 - yolk-citrate extender plus 1.0; 2.0; 3.0 and 4.0% fish oil and 0.05% ascorbic acid, respectively. After thawing, physical evaluations of semen were assessed and additional testing slow heat resistance (TTR), hiposmotic (HO), acrosome integrity and compression of sperm chromatin. There was linear increase (P<0.05) post-thaw motility. No difference was obtained for post-thaw vigor and there was no influence of the association of fish oil and ascorbic acid in TTR. Plasma membrane integrity, by hyposmotic test (HO), presented a mean of reactive spermatozoa of 23.5±5.96% (P>0.05). There was linear increase for intact acrosome and decreasing acrosome irregular (P<0.05). In the analysis of the chromatin compaction, approximately 3% of damages (P>0.05) were observed. The inclusion of 4% fish oil plus ascorbic acid in diluter improved motility and acrosome integrity after cryopreservation.摘要 本研究旨在评估山羊精液冷冻保存（cryopreservation）稀释液中添加鱼油与抗坏血酸联合使用的效果。选取2只波尔公羊（Boer），采用人工阴道法采集精液，随后对每份精液的物理及形态学特征进行检测。检测完成后，将所有精液混合均匀，随后随机分为5组：G1组为卵黄-柠檬酸盐稀释液（yolk-citrate extender）对照组；G2、G3、G4、G5组分别为添加1.0%、2.0%、3.0%、4.0%鱼油与0.05%抗坏血酸的卵黄-柠檬酸盐稀释液。解冻后，对精液进行物理性状评估，并补充开展缓慢耐热试验（slow heat resistance, TTR）、低渗肿胀试验（hyposmotic test, HO）、顶体完整性检测及精子染色质致密性分析。结果显示，解冻后精子运动活力呈线性升高（P<0.05）；解冻后精子活率无显著差异，且鱼油与抗坏血酸联合添加对缓慢耐热试验（TTR）无显著影响。经低渗肿胀试验（HO）检测的质膜完整性指标中，低渗反应精子的平均占比为23.5±5.96%（P>0.05）。完整顶体精子占比呈线性升高，顶体异常精子占比呈线性降低（P<0.05）。染色质致密性分析中，观察到约3%的精子存在染色质损伤（P>0.05）。在稀释液中添加4%鱼油联合抗坏血酸，可提升山羊精液冷冻保存后的精子活力与顶体完整性。