Comparative gut microbiota, growth performances, and cytokine indices in broiler chickens with or without litter

Developmental patterns of the gut microbiota are important for improving chicken health and productivity. However, the influence of litter and litter microbes on cecal microbiota is still unclear. This study aimed to identify broiler cecal microbiota at different ages according to litter usage in cage (without litter) and conventional (with litter) conditions. The cecal contents of the broilers from each group were collected from 1–5 weeks. The development and function of the gut microbiota were evaluated using 16S rRNA gene sequencing. The final body weight of the chickens was higher in the cage group than that in the conventional group. In particularly, α-diversity was higher at 3 weeks than that at 1 week. The phyla Firmicutes and Alistipes predominated at 3 weeks. In contrast, the abundance of Bacteroidetes and fibrinolytic bacteria increased significantly at 1 and 2 weeks compared to that at 3 and 5 weeks. <italic>Corynebacterium </italic>was the most abundant genus in the conventional group after 3 weeks. In conclusion, the cecal microbiota are influenced by environmental factors, such as cage, which improves the chicken gut environment.