为了探讨引起爱拔益加（AA）肉鸡和北京油鸡脂肪沉积表观差异的内在因素，本研究比较了AA肉鸡（56日龄）与北京油鸡（56日龄和114日龄）的体脂沉积、血脂代谢、脂肪细胞因子浓度、脂肪代谢相关酶活性以及相关基因mRNA的表达量。试验选用1日龄AA肉鸡60只和北京油鸡120只，分别随机分为6个重复。结果表明，56日龄AA肉鸡腹脂率高于同日龄的北京油鸡（P<0.05），但是低于114日龄的北京油鸡（P<0.05）。56日龄AA肉鸡血浆总甘油三酯、游离脂肪酸和脂联素浓度，血浆脂蛋白酯酶和肝脏苹果酸脱氢酶活性均低于56日龄和114日龄北京油鸡（P<0.05）。56日龄AA肉鸡肝脏载脂蛋白A-Ⅰ（apoA-Ⅰ）基因mRNA表达量高于56日龄和114日龄北京油鸡（P<0.05），脂联素基因mRNA表达量高于114日龄北京油鸡（P<0.05）。56日龄AA肉鸡腹脂中的甘油三酯脂酶（ATGL）基因和心脏型脂肪酸结合蛋白（H-FABP）基因mRNA表达量高于114日龄的北京油鸡（P<0.05），脂肪型脂肪酸结合蛋白（A-FABP）基因mRNA表达量低于114日龄北京油鸡（P<0.05）；56日龄AA肉鸡腹脂过氧化物酶体增殖物激活受体γ（PPARγ）基因mRNA表达量低于56日龄北京油鸡（P<0.05）。腹脂A-FABP基因mRNA表达量与腹脂率显著正相关（P<0.05）；腹脂ATGL基因、过氧化物酶体增殖物激活受体α（PPARα）基因、肝脏apoA-Ⅰ基因和脂联素基因mRNA表达量均与腹脂H-FABP基因mRNA表达量显著正相关（P<0.05）。结果提示：北京油鸡血浆脂蛋白酯酶和肝脏苹果酸脱氢酶活性高于AA肉鸡，从而导致较高的血浆总甘油三酯和游离脂肪酸浓度，这可能是北京油鸡脂肪沉积较高的内在因素之一。A-FABP基因是造成2个品种腹脂沉积量差异的关键基因，H-FABP基因是脂类代谢通路上的关键基因。

This experiment was conducted to study the internal factors of the apparent difference in fat deposition between Arbor Acres (AA) broilers at the age of 56 days and Beijing-you chickens at the age of 56 and 114 days. One-day-old 60 AA broilers and 120 Beijing-you chickens were randomly assigned to 6 replicates, respectively. The fat deposition, plasma lipid metabolism, concentrations of adipocytokines, enzyme activities, and expression of related genes were investigated. The results showed as follows: the percentage of abdominal fat of AA broilers at the age of 56 days was significantly higher than that of Beijing-you chickens at the same age （P<0.05）, but significantly lower than that of Beijing-you chickens at the age of 114 days （P<0.05）. Beijing-you chickens at the age of 56 and 114 days had higher concentrations of plasma total triglyceride (TG), free fatty acids (FFA) and adiponectin, and activities of plasma lipoprotein lipase (LPL) and hepatic malic dehydrogenase (MDH) than AA broilers at the age of 56 days （P<0.05）. The mRNA expression level of hepatic apolipoprotein A-Ⅰ (apoA-Ⅰ) gene of AA broilers at the age of 56 days was higher than that of Beijing-you chickens at the age of 56 and 114 days （P<0.05）, and adiponectin gene mRNA expression level was higher than that of Beijing-you chickens at the age of 114 days （P<0.05）. Regarding to the abdominal fat, the mRNA expression levels of ATGL and H-FABP genes of AA broilers at the age of 56 days were higher than those of Beijing-you chickens at the age of 114 days （P<0.05）, and A-FABP gene mRNA expression level was lower than that of Beijing-you chickens at the age of 114 days （P<0.05）, and PPARγ gene mRNA expression level was lower than that of Beijing-you chickens at the same age （P<0.05）. There was a positive correlation between A-FABP gene mRNA expression level in abdominal fat and the percentage of abdominal fat （P<0.05）. Positive correlations were also found between the mRNA expression levels of ATGL and PPARα genes in adbdominal fat, apoA-Ⅰ and adiponectin genes in liver, and the mRNA expression level of H-FABP gene （P<0.05）. These results indicate that higher concentrations of plasma TG and FFA induced by higher activities of plasma LPL and hepatic MDH may be one of the reasons of higher fat deposition in Beijing-you chickens. The results also suggest that A-FABP is the key gene that induces the difference of fat deposition between AA broilers and Beijing-you chickens, and H-FABP is the key gene in lipid metabolism pathway. ［Chinese Journal of Animal Nutrition, 2010，22（5）:1334-1341］