| Lots of reports have revealed that high level of copper (> animal needs) could be involved in regulation of lipid metabolism. The experiment was conducted to study the effect of different levels of copper on egg production, lipid metabolism and amounts of Cu, Fe, Mn, Zn in tissue of laying hens to make clear whether high -level copper could influence egg cholesterol and eating safety.Randomization design was introduced in the experiment. 80 New Roman laying hens were randomly divided into 4 treatments, each treatment including 5 replicates with 4 hens per replicate, and were fed diets containing 0,100,250 and 300 mg/kg copper in form of copper sulphate. The hens were fed for 7 days before the formal trial which lasted for 28d .On d 14,21,28, 1 bird was selected from each replicate with 12h fasting and 5 ml blood was obtained from the jugular vein to assay the concentration of cholesterol, TG and VLDL-C in serum. Meanwhile, two eggs were chosen randomly from each replicate to determine contents of yolk cholesterol and Cu, Fe, Mn, Zn. On the last day of the experiment, 1 laying hen was killed by injecting anesthetic to assay GSH and Cu, Fe, Mn, Zn in the liver.The results indicated that there were no statistically significant effects of supplementary 100,250,300 mg Cu /kg on egg production, feed intake ,egg weight through four phases (P>0.05) . But compared to the control group of whole stage, feed intake were increased by 2.41%,5.73%, 2.41%, egg production were enhanced by 5.00%, 2.57%, 0.71%, and egg weight were increased by 4.41%, 3.95%, 1.60% respectively.Compared to the control group , TC per gram yolk at d 14 was significantly reduced(P<0.05) and TC per yolk tended to reduce (P = 0.062) by supplementary 100, 250, 300 mg Cu/kg. Serum TC,TG,VLDL-C were not influenced by copper supplementation. Serum TG , VLDL-C and yolk TC per gram were decreased at d 21 (P<0.05) , serum TC were reduced by 27.53%, 29.12%,...
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