Effects of micronised bamboo powder on growth performance, intestinal development, caecal chyme microflora and metabolic pathway of broilers aged 24–45 days

Context Our previous study revealed that micronised bamboo powder (MBP) can promote the growth performance of broilers aged 1–22 days by improving oxidation resistance, balancing intestinal microflora and regulating metabolic pathways. Aims This study evaluates the effects of MBP on growth performance, intestinal development, caecal chyme microflora and metabolic pathways of broilers during the grower period, age 24–45 days. Methods Slow-growing spotted-brown broilers (n = 880, age 24 days) were randomly divided into two groups according to weight and sex and fed either a maize-based diet (control) or a diet with MBP at 1% replacing equivalent maize. Key results No significant difference was observed in growth performance between MBP and control groups. Broilers receiving MBP exhibited significantly higher (P < 0.05) caecal organ index, jejunum villus height and villi:crypt ratio. The relative abundance of Firmicutes was higher, and relative abundance of Bacteroidetes was lower in the MBP group. Addition of MBP also significantly (P < 0.05) upregulated abundance of p_Firmicutes, f_Alicyclobacillaceae, g_Acutalibacter, f_Peptococcaceae, f_Clostridiaceae, f_Bacillaceae, g_Enterococcus and f_Enterococcaceae, while downregulating abundance of p_Bacteroidetes, f_Bacteroidaceae, g_Bacteroides, o_Bacteroidales and c_Bacteroidia. For the metabolic pathways, 66 were observed to differ between dietary groups, including alanine, aspartic acid and glutamic acid metabolism, butyric acid metabolism, arginine synthesis, linoleic acid metabolism and ß-alanine metabolism. Correlation analysis revealed that Firmicutes in caecal chyme were significantly positively correlated (P < 0.05) with some fatty acids including syringic, 3-methyl-2-oxovaleric, 3-(2-hydroxyphenyl) propanoic and butyric acids. Bacteroidetes were positively correlated (P < 0.05) with some amino acids including L-alanine, L-threonine, 3-methylthiopropionic acid and L-glutamic acid. Conclusions Replacing maize with MBP at 1% had no negative effect on growth performance of broilers. Feeding MBP improved intestinal development and increased the relative abundance of bacteria that promotes fatty acid metabolism and fibre degradation. Implications MBP provides an alternative to maize and is a beneficial source of fibre; further research is warranted to determine the optimum feeding level.