Feed supplementation with α-linolenic acid (ALA) and linoleic acid (LA) increases their content in muscle, ALA increases n-3 polyunsaturated fatty acids and decrease n-6/n-3 ratio in muscle, and LA increases rumenic acid. However, high LA supplementation may have negative effects on lambs’ lipid oxidative stability of meat. When the sources of ALA and LA are fed as fresh forage, the negative effects are counterbalanced by the presence of other bioactive compounds, as vitamin E (mainly α-tocopherol) and polyphenols, which delay the lipid oxidation in meat. There is a wide consensus on the capability of vitamin E delaying lipid oxidation on lamb meat, and its feed content should be adjusted to the length of supplementation. A high dietary inclusion of proanthocyanidins, phenolic compounds and terpenes reduce the lipid oxidation in muscle and may improve the shelf life of meat, probably as a result of a combined effect with dietary vitamin E. However, the recommended dietary inclusion levels depend on the polyphenol type and concentration and antioxidant capacity of the feedstuffs, which cannot be compared easily because no routine analytical grading methods are yet available. Unless phenolic compounds content in dietary ingredients/supplements for lambs are reported, no specific association with animal physiology responses may be established.

中文翻译：

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深入了解主要生物活性膳食营养素在羊肉品质中的作用：综述

饲料中添加 α-亚麻酸 (ALA) 和亚油酸 (LA) 会增加它们在肌肉中的含量，ALA 会增加肌肉中的 n-3 多不饱和脂肪酸并降低 n-6/n-3 比值，而 LA 会增加瘤胃酸。然而，高 LA 补充剂可能对羔羊肉的脂质氧化稳定性产生负面影响。当 ALA 和 LA 的来源作为新鲜草料饲喂时，负面影响被其他生物活性化合物的存在抵消，例如维生素 E（主要是 α-生育酚）和多酚，它们可以延缓肉类中的脂质氧化。维生素E延缓羊肉脂质氧化的能力已达成广泛共识，应根据补充时间调整其饲料含量。高膳食中的原花青素，酚类化合物和萜烯可减少肌肉中的脂质氧化，并可能延长肉类的保质期，这可能是与膳食维生素 E 共同作用的结果。然而，推荐的膳食添加水平取决于多酚的类型、浓度和抗氧化能力由于目前还没有常规的分析分级方法，因此无法轻松比较饲料。除非报告了羔羊膳食成分/补充剂中的酚类化合物含量，否则无法确定与动物生理反应的具体关联。由于还没有常规的分析分级方法可用，因此无法轻松进行比较。除非报告了羔羊膳食成分/补充剂中的酚类化合物含量，否则无法确定与动物生理反应的具体关联。由于还没有常规的分析分级方法可用，因此无法轻松进行比较。除非报告了羔羊膳食成分/补充剂中的酚类化合物含量，否则无法确定与动物生理反应的具体关联。