Abstract: This study was conducted to investigate the effect of different ages on intestinal micro-ecology of the giant pandas. Fresh feces of the giant pandas (Ailuropoda melanoleuca) under different ages[J₁ (sub-adult giant panda), J₂ (adult giant panda) and J₃ (old giant panda)] were collected. The bacterial composition in the feces was determined by 16S rRNA gene technology. The physical and chemical characteristics as well as activities of specific enzymes were analyzed. The correlation between the fecal microbiota and the fecal environmental factors of the giant pandas were analyzed by redundant analysis (RDA). The results showed that the relative abundance of the Proteobacteria increased with age at the phylum level. The relative abundance of Firmicutes decreased with age. The relative abundance of Streptococcus decreased with age at the genus level. The activity of amylase and cellulose were the highest in the feces of the J₂, the activity of amylase was the lowest in the feces of J₃, and the activity of cellulase was the lowest in the feces of J₁. The activity of protease was the highest in the feces of J₁, and the lowest in the feces of J₃. The relative abundance of Firmicutes and Bacteroidetes were positively correlated with amylase activity and reducing sugar content. The relative abundance of Proteobacteria was negatively correlated with reducing sugar content and amino acid content. The study showed that the fecal microbial of the giant pandas of different ages exhibited different characteristics. The relative abundance of dominant bacteria in the feces of the giant pandas was correlated with environmental factors such as fecal digestive enzymes. It is suggested that the diet and living environment of the sub-adult giant pandas should be improved, and probiotics can be added to the diet in order to improve gut health of the old giant pandas.

Key words: giant panda (Ailuropoda melanoleuca), age, feces, microbiota, digestive enzymes, redundant analysis