本试验旨在研究品种、日龄和饲养方式对鸡肉肌苷酸（IMP）和肌内脂肪（IMF）含量的影响及其互作效应。选取爱拔益加（AA）肉鸡和北京油鸡各240只，每个品种均分笼养和地面平养2种饲养方式，每种饲养方式120只鸡（均为6个重复，每个重复20只），在21和42日龄分别比较2种饲养方式下鸡的胸肌IMP和IMF含量，并分析其脂肪酸组成。结果表明：1）IMP含量北京油鸡显著高于AA肉鸡（P<0.05），42日龄显著高于21日龄（P<0.05），品种和日龄对鸡肉IMP含量的影响存在显著的互作效应（P<0.05）；2）IMF含量北京油鸡显著高于AA肉鸡（P<0.05），42日龄显著高于21日龄（P<0.05），笼养显著高于平养（P<0.05），3个因素对鸡肉IMF含量的影响无显著的互作效应（P>0.05）；3）脂肪酸含量除C18∶2和C24∶0为北京油鸡显著高于AA肉鸡（P<0.05）外，其余脂肪酸则为AA肉鸡显著高于北京油鸡（P<0.05）；AA肉鸡不饱和脂肪酸含量及其与饱和脂肪酸的比例显著高于北京油鸡（P<0.05）；除C18∶0、C20∶0和C22∶0外，品种对其他脂肪酸含量均有显著影响（P<0.05），日龄对脂肪酸含量无显著影响（P>0.05），平养显著降低了饱和脂肪酸含量及其与不饱和脂肪酸的比例（P<0.05）；3个因素对鸡肉脂肪酸含量的影响无显著的互作效应（P>0.05）。由此可知，北京油鸡鸡肉的IMP和IMF含量以及脂肪酸C18∶2和C24∶0含量显著高于AA肉鸡，42日龄鸡鸡肉的IMP和IMF含量显著高于21日龄鸡，平养鸡鸡肉的IMF含量、饱和脂肪酸C14∶0、C18∶0、C20∶0和C22∶0含量以及饱和脂肪酸与不饱和脂肪酸的比例均显著低于笼养鸡，品种和日龄对鸡肉的IMP含量有显著的交互作用。

The trial was conducted to investigate the effects of breed, age and feeding regime on the contents of inosine-5′-monophosphate (IMP) and intramuscular fat (IMF) in chicken meat and the interactions among influencing factors. A total of 240 Arber Acres (AA) broilers and 240 Beijing fatty chickens were both divided into two groups fed in two feeding regime (in cages or on the floor, respectively), thus there were 120 chickens for each Feed style, which contained 6 replicates with 20 chickens each. On day 21 and 42, the IMP and IMF contents of chicken meat were compared and fatty acid composition was analyzed. The results showed as follows: 1) the IMP content in chicken meat of Beijing fatty chickens was higher than that of AA broilers (P<0.05), for which, 42-d-old chickens was higher than 21-d-old chickens (P<0.05), and there was a significant interaction between breed and age (P<0.05); 2) the IMF content in chicken meat of Beijing fatty chickens was higher than that of AA broilers (P<0.05), for which, 42-d-old chickens was higher than 21-d-old chickens (P<0.05), and chickens in cages were higher than those on the floor (P<0.05), and no interactions among breed, age and feeding regime were observed (P>0.05); 3) except C18∶0 and C22∶0, other fatty acid contents were significantly affected by breed; for C18∶2 and C24∶0, Beijing fatty chickens were higher than AA broilers (P<0.05), when it came to other fatty acids, it was reversed (P<0.05). The content of unsaturated fatty acids and its ratio to the content of saturated fatty acids in the meat of Beijing fatty chickens were higher than those of AA broilers (P<0.05); age had no effects on the composition of fatty acids in chicken meat (P>0.05); feeding on the floor significantly increased the content of saturated fatty acids and its ratio to the content of unsaturated fatty acids in the meat (P<0.05); the interactions among the three influencing factors were not observed in the contents of fatty acids (P>0.05). So a conclusion can be drawn that IMP, IMF and fatty acid C18∶2 and C24∶0 contents in the meat of Beijing fatty chickens are significantly higher than those of AA broilers; IMP and IMF contents in the meat of 42-d-old chickens are significantly higher than those of 21-d-old chickens; the contents of IMF, saturated fatty acids C14∶0, C18∶0, C20∶0 and C22∶0, and the ratio of saturated fatty acids to unsaturated fatty acids in the meat of chickens fed on the floor are significantly lower than those of chickens fed in cages. There is a significant interaction between breed and age on the content of IMP in chicken meat.［Chinese Journal of Animal Nutrition, 2010，22（5）:1251-1256］