Abstract: 【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.

Key words: Sheep, Selenium, Polyunsaturated fatty acid, Antioxidant