硒和脂肪酸对绵羊血浆和红细胞膜脂肪酸组成及抗氧化影响

【目的】研究日粮中不同硒（Se）水平和不同来源多不饱和脂肪酸（PUFA）对绵羊血浆和红细胞膜脂肪酸组成及抗氧化的影响。【方法】选用3月龄三元杂交肉用羯羊（无角陶赛特×小尾寒羊×夏洛莱，平均体重为26.3±1.2 kg）32只作为试验羊，采用2×2因子（两个Se水平和两个PUFA来源）设计，随机分为4组，分别饲喂基础日粮＋5%亚麻油（LO）、LO＋2 mg•kg-1硒（LOSe）、基础日粮＋5％葵花油（SO）和SO＋2 mg•kg-1硒（SOSe）。硒以亚硒酸钠的形式添加。试验结束后颈静脉采血，分离血浆及红细胞膜，测定脂肪酸组成及抗氧化特征。【结果】日粮加硒提高了绵羊血浆和红细胞膜的抗氧化能力、血浆trans-11-C18:1浓度和红细胞膜trans-10,cis-12-C18:2浓度，增加了饲喂葵花油日粮绵羊血浆中C20:4n-6和红细胞膜中C20:5n-3浓度，对饲喂亚麻油日粮绵羊无影响；饲喂亚麻油日粮绵羊比饲喂葵花油日粮绵羊血浆和红细胞膜中PUFA更易发生脂质过氧化反应。【结论】绵羊饲喂富含PUFA日粮，同时添加硒可提高血浆和红细胞膜的抗氧化能力，促进PUFA的沉积；添加硒更有利于饲喂葵花油日粮绵羊血浆和红细胞膜中的PUFA沉积。

Effect of Selenium and Fatty Acid on Plasma and Erythrocytic Membrane Fatty Acid Composition and Antioxidant Status in Lambs

【Objective】The purpose of this experiment was to study the effects of different selenium (Se) level and polyunsaturated fatty acid (PUFA) source on plasma and erythrocytic membrane fatty acid composition and antioxidant status in lambs. 【Method】Thirty-two wether lambs (Chinese Poll Dorset × Small Tailed Han × Charolais) with 3 month old were used and the experiment was a 2 × 2 factorial (two Se levels and two PUFA sources) design. The lambs were divided into 4 groups and each supplied one of the following diets: basal diet + 5% linseed oil (LO); LO + 2 mg/kg Se (as sodium selenite) (LOSe); basal diet + 5% sunflower oil (SO); SO + 2 mg/kg Se (SOSe). Blood samples of each animal were obtained by venipuncture from the jugular prior to the morning meal on the last day of the experiment and then transferred to the tube containing EDTA (1.5 mg/ml blood). The plasma and erythrocytic membrane were obtained to analysis the fatty acid composition and antioxidant status.【Results】Se supplementation increased the antioxidant status, the concentration of trans-C18:1 in plasma and trans-10,cis-12-C18:2 in erythrocytic membrane. Se supplementation also increased the concentration of C20:4 in plasma and C20:5 in erythrocytic membrane in lambs fed the sunflower oil diet; the PUFA in plasma and erythrocytic membrane was more easily oxidated in lambs fed the linseed oil diet.【Conclusion】Se supplementation increased the antioxidant status and deposition of PUFA in plasma and erythrocytic membrane when lambs fed PUFA diet. Selenium supplementation increased more PUFA deposition in lambs fed sunflower oil diet than fed linseed oil diet.