an increasing trendP < 0.1
6 C and D, compared with cage broilers, ground litter broilers had higher ileal microbial α diversity ( P < 0.05), d 28 Shannon, Simpson and Chao1 indices were higher ( P < 0.05), and d 10 observed species, Shannon and Chao1 had an increasing trend (0.05 < P < 0.1).