选取体重（12.09±1.70 kg）及年龄 (60±5d) 相近的48头雄性乐至黑山羊研究肉山羊饲粮中添加铜(试剂级五水硫酸铜)对其生长性能、血清脂类代谢以及脂肪代谢相关的基因表达的影响。肉羊按照完全随机试验设计分为4个处理组。每个处理组12个重复（以栏为重复单位），每个重复1头羊羔，单栏单饲。对照组肉羊饲喂不含铜的基础饲粮，其它3个处理组肉羊饲粮为在基础饲粮基础上分别添加10 mg kg^-1, 20mg kg^-1或30mg kg^-1铜。各组饲粮为高精颗粒饲料，试验期60天。试验结果表明，饲粮不同铜添加水平对肉山羊的平均日增重、平均日采食量以及料重比没有影响（P>0.05）；肉羊血清总胆固醇、甘油三酯及高密度脂蛋白胆固醇的浓度也未受到饲粮铜浓度的影响（P>0.05），但随着饲粮铜浓度的增加血清低密度脂蛋白胆固醇的浓度线性降低（P=0.01）。随着饲粮铜浓度增加，背最长肌肌内脂肪含量呈二次曲线上升(P=0.002)，肝脏铜浓度呈线性上升(P<0.001)。与对照组相比，饲粮添加20mg kg^-1铜降低了背最长肌中脂肪酸结合蛋白4 (P=0.01)和脂蛋白脂酶 (P=0.05)的mRNA表达，肉碱棕榈酰转移酶I的mRNA表达也呈现下降的趋势(P=0.06)；肝脏中过氧化物酶体增殖物激活受体α (P<0.001)、肉碱乙酰转移酶(P=0.001)和肉碱棕榈酰转移酶I(P=0.001) 的mRNA表达也随着饲粮添加铜而降低。以上结果表明，肉山羊饲粮中添加铜可通过增加肌内脂肪及降低血清低密度脂蛋白胆固醇来调节脂质代谢，而这种调节可能与肉山羊肌肉和肝脏中长链脂肪酸氧化基因的mRNA表达的降低有关。本研究结果将有助于进一步理解微量元素铜在肉山羊脂类代谢中的作用，为铜添加剂在肉山羊中的应用提供理论基础。

Forty-eight male Lezhi black goat kids with similar body weight ((12.09±1.70) kg) and age ((60±5) d) were used to determine the effect of dietary copper (Cu), in the form of reagent grade Cu sulfate (CuSO₄∙5H₂O), on performance, serum lipid profile, and the relative mRNA abundance of genes involved in lipid metabolism.  Goat kids were stratified by body weight and randomly assigned to one of 4 treatment groups.  Each treatment consisted of 12 replicate pens with each pen containing one goat kid.  Treatment groups received the basal diet with no supplemental Cu (control), basal diet plus 10 mg of Cu kg^–1 of dry matter (DM), basal diet plus 20 mg of Cu kg^–1 of DM, or basal diet plus 30 mg of Cu kg^–1 of DM.  Goats were housed individually in pens and fed a high-concentrate pelleted diet for 60 d.  Average daily gain, average daily feed intake and feed:gain of goats were not affected by dietary Cu supplementation (P>0.10).  No differences were detected in serum total cholesterol, triglyceride, and high density lipoprotein cholesterol concentrations of goat kids fed with different Cu concentrations (P>0.05).  However, serum low density lipoprotein cholesterol concentrations decreased linearly (P=0.01) as the concentration of dietary Cu increased.  Intramuscular fat content of longissimus muscle increased (P=0.002) quadratically and liver Cu concentrations increased (P<0.001) linearly as dietary Cu concentration increased.  Compared with the control, dietary supplementation of 20 mg Cu kg^–1 DM decreased the relative mRNA abundance of fatty acid-binding protein 4 (P=0.01) and lipoprotein lipase (P=0.05), and tended to decrease the relative mRNA abundance of carnitine palmitoyltransferase I (P=0.06) in longissimus muscle of goats.  The relative mRNA abundance of peroxisome proliferator-activated receptor alpha (P<0.001), carnitine acetyltransferase (P=0.001), and carnitine palmitoyltransferase I (P=0.001) were also decreased in liver by Cu supplementation.  These results indicate that dietary supplementation of Cu modified lipid metabolism by increasing muscular fat and decreasing serum low density lipoprotein cholesterol, and the modification might be associated with the reduction of relative mRNA abundance of genes for oxidation of long-chain fatty acid in muscle and liver of Lezhi black goat kids.