Analysis of differences in gut microbiota structure and function in Bactrian camels under different breeding patterns...

The lactating Xinjiang Junggar camel is a major dairy breed with excellent milk production performance. In northern Xinjiang, camels are mainly reared under traditional grazing, while those in southern Xinjiang are raised under barn feeding due to grassland scarcity.

Nine lactating camels aged 6-7 years old and nine juvenile camels aged 8 months old were selected from each region. Fresh fecal samples were collected from the rectum of each camel for metagenomic sequencing analysis.

The findings indicated that the diversity and abundance of gut microbiota in the BJT group were significantly increased compared with those in the NJT group. Furthermore, the diversity and abundance of gut microbiota in adult lactating camels from both regions were superior to those in juvenile camels. Among the gut microbiota, Actinomycetota, Campylobacterota, Ascomycota, and Thermoplasmatota presented significantly higher relative abundance in the BJT group than in the NJT group (p < 0.05). The relative abundance of Acinetobacter and Halomonas was also significantly elevated in the BJT group, whereas Escherichia and Prevotella were significantly less abundant. Furthermore, the relative abundance of Bifidobacterium and Lactobacillus declined significantly in adult lactating camels compared to that in juvenile camels. There were notable differences in the functional annotations of metabolic pathways, suggesting that the gut microbiota in the BJT group was primarily engaged in nitrogen cycling, decomposition of various organic compounds, and fatty acid metabolism, which were linked to nutrient metabolism, detoxification, and biosynthesis. In contrast, the gut microbiota in the NJT group was associated with such functions as cell recognition, signal transduction, and immune response. Glycoside Hydrolases and Glycosyltransferases constituted the primary carbohydrate-active enzymes within the gut microbiota in Bactrian camels, and they were conducive to the degradation of plant cellulose.

Since the intestines of juvenile camel are in the developmental stage, the genera Bifidobacterium and Lactobacillus potentially play significant roles in intestinal maturation. Notably, the gut microbiota in Bactrian camels from northern Xinjiang are characterized by high relative abundance of microorganisms that are halophilic and involved in crude fiber degradation. In contrast, Bactrian camels under barn feeding in southern Xinjiang exhibit higher abundance of the genera Escherichia and Prevotella, implying geographical and feeding conditions are associated with the variations in gut microbiota variations.