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

Abstract

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 β-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.