Health and performance are important aspects in the broiler industry. Underlying complex traits like total mean weight and feed efficiency are polygenic and related to genetic background and an association of the microbiota with these traits has been identified. Whether this association is also reflected in the fecal samples of broilers is not extensively investigated. The objective of this study was to investigate to what extend diet, genetics, and environment influence the fecal microbiome composition during the life time of broilers.

Two experiments were performed, in the first experiment the focus was on investigating if a European (EU) or United States (USA) diet effects the fecal microbiota in a commercial line (Cobb500). Whereas in the second diet (EU/USA) and lines with a genetic background (EU/USA) were investigated in relation to the fecal microbiota.

In the first experiment we observed a significant effect in commercial broiler line (Cobb500) of the 3-way interaction for age by feed by sex on Total Mean Weight (TMW), and the 2-way interaction of age by feed for Feed Conversion Ratio (FCR). For the microbiota data, we observed differences in alpha-diversity for Age. When comparing the diets on a time-point, this resulted in significant differences for Observed species at day 21 and for Observed species, Shannon index, and Pielou's evenness at day 35. In the beta-diversity, a significant effect of age by feed interaction was observed. Two genera were significantly different in feces of broilers between diets, i.e. Streptococcus on day 7 and Bilophila on day 21.

In the second experiment we observed only a significant effect for the main effect age on TMW. Alpha-diversity showed a significant increase for all three measures for age. Furthermore, a significant effect of environment was observed in the Observed species. This effect of environment was also observed in the beta-diversity, where a significant effect for age and environment was observed. This environmental effect was not expected, because here environment represents two different compartments within the same stable, unfortunately it was not possible to perform further down-stream analyses.

This research shows the different aspects (feed, sex, genetics, and environment) influence complex traits, like TMW and FCR and are affecting the fecal microbiome. We have shown that interventions, like feed and the effect on microbiome, are reproducible between experiments. Moreover, these results with these two genetic divers chicken lines suggest that the succession of the fecal microbiota was independent of genetic background.

健康和性能是肉鸡行业的重要方面。潜在的复杂性状（如总平均体重和饲料效率）是多基因的，并且与遗传背景有关，并且已经确定了微生物群与这些性状的关联。这种联系是否也反映在肉鸡粪便中，尚未得到广泛研究。这项研究的目的是调查在肉鸡的生命周期中，饮食，遗传学和环境对粪便微生物组组成的影响程度。

进行了两个实验，在第一个实验中，重点是研究欧洲（EU）或美国（USA）饮食是否会影响商业化产品系列（Cobb500）中的粪便微生物群。而在第二种饮食（欧盟/美国）和具有遗传背景的品系（欧盟/美国）中，对粪便微生物群进行了调查。

在第一个实验中，我们观察到在商业肉鸡线（Cobb500）3双向互动的显著效果的年龄由饲料通过性上总的平均重量（TMW），和2路的相互作用年龄由饲料的饲料转化率（FCR）。对于微生物群数据，我们观察到了年龄的阿尔法多样性差异。当比较在时间点的饮食，这导致在第21天观察到的物种显著差异和观察种，Shannon指数，而均匀度的，在35天的均匀性的β多样性的显著效果年龄由饲料观察到相互作用。两种日粮的肉鸡粪便之间存在明显差异，即第7天的链球菌和第21天的嗜肉菌。

在第二个实验中，我们只观察到主效应年龄对TMW有显着影响。三种年龄指标都显示出阿尔法多样性显着增加。此外，在被观察物种中观察到了环境的显着影响。在beta多样性中也观察到了这种环境影响，其中观察到了对年龄和环境的显着影响。预期不会产生这种环境影响，因为此处的环境代表同一稳定内的两个不同隔室，很遗憾，无法进行进一步的下游分析。

这项研究表明，不同的方面（饲料，性别，遗传学和环境）影响复杂的特征，如TMW和FCR，并影响粪便微生物组。我们已经证明，在实验之间可以重现诸如饲料和对微生物组的影响之类的干预措施。此外，这两个遗传潜水员鸡系的这些结果表明，粪便微生物群的演替与遗传背景无关。