背景:在中国,具有高空间利用率的笼子系统已逐渐取代地面垃圾系统,但是鸡笼中的鸡的发病率更高。地面垫料圈中的肉鸡在生长过程中可能受到更多环境微生物的刺激,表现出较强的免疫功能和状态,但是,对哪些微生物及其代谢产物发挥免疫调节作用的知识仍然有限。本研究旨在探讨免疫功能的差异和相关性,肠道菌群和代谢产物以及在笼子和地面垫料圈中饲养的肉鸡肠道菌群的重要性。
方法:实验涉及2×2阶乘排列,以饲养系统(笼子或垃圾围栏)和抗生素治疗(在饮用水中使用或不使用广谱抗生素)为因素。
结果:结果表明,与笼组相比,地上窝肉鸡具有更强的非特异性免疫功能(巨噬细胞%和血液中的NO),体液免疫功能(血液中的IgG,回肠LPS刺激指数)和细胞免疫功能(T%,Tc%,ConA刺激指数和血液中的细胞因子)。抗生素(ABX)治疗显着降低非特异性免疫功能(血液中的巨噬细胞百分比和NO,回肠中iNOS和Mucin2mRNA的表达),体液免疫功能(血液中的IgG和回肠中的sIgA)和细胞免疫功能(血液中的T%和细胞因子,Th和Tc比,回肠中的TLRs和细胞因子mRNA表达)。此外,地面凋落肉鸡回肠内微生物群α多样性较高。葡萄球菌的相对丰度,无节虫,地面凋落肉仔鸡回肠中的重性杆菌和片球菌含量较高。ABX治疗显著降低了回肠微生物群的α多样性,叶绿体和线粒体较少。此外,乙酸的含量,异丁酸,地面凋落肉鸡回肠中的犬尿烯酸和同种脲胆酸含量较高。Spearman相关分析表明,片球菌,乙酸,犬尿烯酸和同种卵胆酸与免疫功能有关。
结论:有更多的潜在病原体,凋落物繁殖细菌,短链脂肪酸,犬尿氨酸,地面垫料围栏中肉鸡回肠中的同种胆酸和色氨酸代谢产物,这可能是其更强的免疫功能和状态的原因。
BACKGROUND: In
China, cage systems with a high space utilization have gradually replaced ground litter systems, but the disease incidence of chickens in cages is higher. Broilers in the ground litter pens may be stimulated by more environmental microbes during the growth process and show strong immune function and status, but knowledge of which microbes and their metabolites play an immunomodulatory role is still limited. This study aimed to explore the differences and correlations in the immune function, gut microbiota and metabolites and the importance of gut microbiota of broilers raised in cages and ground litter pens.
METHODS: The experiment involved a 2 × 2 factorial arrangement, with rearing systems (cages or ground litter pens) and antibiotic treatment (with or without broad-spectrum antibiotics in drinking water) as factors.
RESULTS: The results showed that, compared with the cage group, the ground litter broilers had stronger nonspecific immune function (Macrophages% and NO in blood), humoral immune function (IgG in blood, LPS stimulation index in ileum) and cellular immune function (T%, Tc%, ConA stimulation index and cytokines in blood). Antibiotic (ABX) treatment significantly reduced nonspecific immune function (Macrophages% and NO in blood, iNOS and Mucin2 mRNA expression in ileum), humoral immune function (IgG in blood and sIgA in ileum) and cellular immune function (T% and cytokines in blood, Th and Tc ratio, TLRs and cytokines mRNA expression in ileum). Furthermore, the ground litter broilers had higher α diversity of microbiota in ileum. The relative abundance of Staphylococcus, Jeotgalicoccus, Jeotgalibaca and Pediococcus in the ileum of ground litter broilers were higher. ABX treatment significantly reduced the α diversity of ileal microbiota, with less Chloroplast and Mitochondria. In addition, the levels of acetic acid, isobutyric acid, kynurenic acid and allolithocholic acid in the ileum of ground litter broilers were higher. Spearman correlation analysis showed that Jeotgalibaca, Pediococcus, acetic acid, kynurenic acid and allolithocholic acid were related to the immune function.
CONCLUSIONS: There were more potential pathogens, litter breeding bacteria, short-chain fatty acids, kynurenine, allolithocholic acid and tryptophan metabolites in the ileum of broilers in ground litter pens, which may be the reason for its stronger immune function and status.