Effect of dietary conjugated linoleic acid on the lipid peroxidation of the breast muscle and the thigh muscle of broiler chickens | 日粮中添加共轭亚油酸对肉仔鸡胸肌和腿肌脂质过氧化状态的影响

Chinese. 研究日粮中添加共轭亚油酸（Conjugated linoleic acid,CLA）对肉仔鸡胸肌和腿肌脂质过氧化状态的影响及原因。将96只1日龄AA（Arbor Acre）雄性肉仔鸡用玉米-豆粕日粮饲喂至3周龄，在3周龄末，将其随机分为对照组和CLA组，分别饲喂基础日粮和CLA日粮，每处理8个重复，每重复6只鸡。42日龄时屠宰，剥离胸肌和腿肌，检测其中的脂肪酸组成和脂质过氧化相关指标。日粮中添加CLA降低了肉仔鸡胸肌和腿肌的丙二醛（MDA）(P＜0.01)和活性氧含量(P＜0.05)。2组肉仔鸡腿肌和胸肌中各种抗氧化酶活性无显著差异 (P＞0.05)。与对照组相比，CLA组肉仔鸡胸肌和腿肌的谷胱甘肽含量分别提高了21.89％和21.56%(P＜0.01)，γ-谷氨酰半胱氨酸合成酶的活性分别提高了28.57％和25.80%(P＜0.01)。日粮中添加CLA提高了肉仔鸡胸肌和腿肌总CLA(P＜0.01)及饱和脂肪酸（SFA）含量(P＜0.05)，极显著降低了单不饱和脂肪酸含量(P＜0.01)。日粮中添加CLA改变了肉仔鸡胸肌和腿肌脂肪酸的组成，提高了脂质稳定性，同时增加了GSH含量，淬灭了更多的自由基，从而降低了脂质过氧化水平。

English. The present study was conducted to investigate effect of conjugated linoleic acid (CLA) on the lipid peroxidation of the breast muscle and the thigh muscle of broiler chickens and cressponding mechanism. Ninety six 1-day-old male AA (Abor Acre) broiler chickens were supplemented with the same maize-soybean meal diet until the end of the third week, and then were randomly allocated into control group and 1.5% CLA supplementation group, supplemented with control diet and CLA supplementation diet respectively, each treatment with eight replicates of 6 chickens. The brolier chickens were excuted at 42 days old, and the breast muscle and the thigh muscle were excised. The fatty acid composition and lipid peroxidation pertinent index were detected. Results showed that dietary CLA supplementation significantly decreased malondialdehyde (MDA) concentration (P＜0.01) and reactive oxygen species (ROS) production (P＜0.05) in the breast muscle and the thigh muscle. There was no difference in antioxidant enzyme activity between two groups (P0.05). Compared with control group, glutathione (GSH) in breast muscle and thigh muscle of brolier chickens from 1.5% CLA supplementation group increased by 21.89％(P＜0.01) and 21.56% (P＜0.01) respectively, while γ-glutamylcysteine synthetase（γ-GCS）activity increased by 28.57％ (P＜0.01) and 25.80% (P＜0.01) respectively. Dietary CLA supplementation significantly increased CLA (P＜0.01) and saturated fatty acid (SFA) (P＜0.05), decreased monounsaturated fatty acid (MUFA) in the breast muscle and thigh muscle of broiler chickens (P＜0.01). Our results showed that dietary CLA may decrease lipid peroxidation in breast muscle and thigh muscle of broiler chickens through the following ways: First, dietary CLA influenced the fatty acid composition and increased oxidative stability of the thigh muscle and breast muscle; Second, increased γ-GCS activity and then induced GSH synthesis, consequently more ROS was scavenged.