中文摘要：

本研究旨在探讨日粮铜来源及水平对肉鸡肝铜沉积及其组织病理学变化的影响。288只1日龄肉鸡随机分为8组，每组6个重复，每个重复6只鸡。选用硫酸铜、蛋氨酸铜作为试验铜源，每种铜源均设4个水平，分为对照日粮（Cu11mg／kg）和高铜日粮（Cu110mg／kg；Cu220mg／kg；Cu330mg／kg）。试验期60d，并于12、36和60日龄采血，测定血清中丙氨酸氨基转移酶（ALT）和天门冬氨酸氨基转移酶（AsT）的活性，60日龄取肝脏，测定肝铜沉积量并观察肝损伤情况。结果表明：2种来源日粮铜组随着铜水平的增加，肝铜沉积量存在普遍升高的趋势，当日粮铜水平达到330mg／kg时，除12日龄蛋氨酸铜组外，其他各组肝铜沉积量均显著高于对照组（P〈0．05），并具有时间依赖性；铜源之间比较，除11mg／kg铜水平（对照组）外，在肉鸡36和60日龄时，硫酸铜各组肉鸡肝铜沉积量要低于相应的蛋氨酸铜组（P〈0．05）。随着日粮铜水平和日龄的增加，血清ALT和AST活性大部分呈现升高趋势，与对照组比较，220和330mg／kg日粮铜均可显著提高肉鸡36和60日龄血清ALT、AST活性（P〈0．05）。铜源之间比较，在肉鸡36和60日龄时，330mg／kg蛋氨酸铜组的肉鸡血清ALT和AST活性显著高于330mg／kg硫酸铜组（P〈0．05）。60日龄时，高水平日粮铜可造成肝细胞肿胀、胞浆内颗粒变性、肝细胞索和肝窦结构模糊等组织病理变化，在电子显微镜下则可见到胞浆内吞饮空泡增多、线粒体膜模糊和形态不规则、胞浆和核内出现电子密度沉积体等病理学损伤。结果提示：高铜日粮可增加肉鸡肝铜沉积，肝功能受到抑制，并导致肝脏出现不同程度的病理学损伤，相同添加水平的蛋氨酸铜比硫酸铜可导致更多的肝铜沉积，也相应地出现肝功能下降及组织病理学损伤。

英文摘要：

The trial was conducted to study the effects of dietary copper levels of different sources on copper deposition and histopathological changes of liver of broilers. Two hundred and eighty-eight 1-day-old broilers were randomly divided into 8 groups, and there were 6 replicates in each group and 6 broilers in each replicate. The coppers were from CuSO4 and Cu-Met and they were respectively designed to four dietary levels containing control （11 mg/kg） and high levels （110, 220 and 330 mg/kg）. The trial lasted for 60 days. The blood samples were obtained at 12, 36 and 60 d respectively to investigate ALT and AST activities, and the liver samples were processed at 60 d to investigate copper deposition and histopathological changes of broiler. The results showed that liver copper deposition of broiler in groups of two copper sources tended to increase with the increasing of dietary copper levels, and it was higher than that in control except that of 12 day-old broilers in Cu-Met group when dietary copper level was 330 mg/kg （P〈0.05）, and it had the effect of age-dependent; compared between the two copper sources, liver copper deposition of 36 and 60 day-old broilers in CuSO4 group was lower than that in Cu-Met group except that in control （P〈0.05）. The activities of ALT and AST in serum tended to increase with the increasing of the dietary copper level and age of broilers, and 220 and 330 mg/kg copper increased significantly the activities of ALT and AST in serum of 36 and 60 day-old broilers compared with the control; compared between the two copper sources, the activities of ALT and AST in serum of 36 and 60 day-old broilers in 330 mg/kg Cu-Met group was higher than that in 330 mg/kg CuSO4 group （P〈0.05）. At 60 days old, high dietary copper levels caused some obvious histopathological changes of hepatocyte swelling, granules degeneration in cytosolic, fuzzy structure of hepatocyte cable and liver sinusoidal under light microscope, and presented engulfing vesicle in cytosolic, fuzzy mitoehond