Abstract: This study was conducted to evaluate the effects of grazed in an artificial mixture under forest on muscle nutritional quality and intestinal microflora of Beijing-you chickens. The artificial mixture was established with a mixture of chicory (Cichorium intybus L.),perennial ryegrass (Lolium perenne L.) and annual ryegrass (Lolium multiflorum L.). Nine-week-old female Beijing-you chickens with similar body weight were randomly assigned to three free-grazing groups:bare land with a stocking density of 90 hens·667 m^-2 (CK);grazed in an artificial mixture under forest with two stocking density of 90 hens·667 m^-2 (T1) and 120 hens·667 m^-2 (T2),respectively. All chickens of those three groups were raised to 21 weeks old to investigate their muscle nutritional quality and intestinal microflora. The results revealed that chickens in T1 and T2 had increased total amino acids and essential amino acids contents of breast and thigh muscle (P<0.05),chickens in T2 also had increased delicious amino acids contents of thigh muscle (P<0.05). In addition,T1 and T2 decreased microbial community richness and diversity in duodenum (P<0.05),increased the relative abundance of beneficial bacteria (P<0.05),such as Lactobacillus,in duodenum. There were no differences in the structures of microbial communities in ileum and cecum among the three tested groups. In conclusion,grazed in an artificial mixture under forest significantly improved amino acid quality in muscle of chickens,which might be due to the change of the beneficial duodenal microflora of chickens.

Key words: Artificial mixture under forest, Beijing-you chicken, Muscle nutritional quality, Intestinal microflora

摘要： 本试验旨在研究林下“菊苣(Cichorium intybus L.)+多年生黑麦草(Lolium perenne L.)+一年生黑麦草(Lolium multiflorum L.)”混播草地放养对北京油鸡肌肉营养品质及肠道菌群的影响。将体重相近的9周龄北京油鸡母鸡随机分为3组：林下清耕地散养组(养殖密度90只·667 m^-2，CK)、林下混播草地放养组(设置2个养殖密度，即90只·667 m^-2(T1)和120只·667 m^-2(T2))，采用划区轮牧的方式饲养至21周龄。结果表明:与CK组相比，T1和T2组显著提高了胸肌和腿肌的总氨基酸和必需氨基酸含量(P<0.05)，T2组还显著提高了腿肌的鲜味氨基酸含量(P<0.05)。此外，T1和T2组显著降低了十二指肠菌群丰富度和多样性(P<0.05)，十二指肠菌群中益生菌Lactobacillus相对丰度也得到显著提高(P<0.05)，但对回肠和盲肠菌群结构无影响。综上所述，林下混播草地放养显著提升了肌肉氨基酸品质，这可能与十二指肠菌群结构发生改变有关。

关键词: 林下混播草地, 北京油鸡, 肌肉营养品质, 肠道菌群