Developmental And Varietal Characteristics Of The Intestinal Microbiota And Related Metabolites Of Wenchang Chickens In Hainan Province

Studies about intestinal microbiota and its metabolites have been increasing their essential role in animal growth by affecting the intake,storage,absorption and utilization of nutrients in the host.Besides dietary factors,differences in growth stages,varieties and feeding models alters the composition and characteristics intestinal flora.However,studies on the development of intestinal microbiota and its metabolites in Hainan local chickens currently remains limited and obscure.In this study,we sampled cecum chyme from Wenchang hens of six growth stages(01d,27 d,53d,105 d,133d,161d).12 individuals with the same feeding and similar weight were grouped together in each stage.We also performed cecum chyme sampling on Wenchang chickens(half caged and half free-ranged),Danzhou chickens(free-ranged)and Sanhuang chickens(caged)at the same growth stage under market breeding conditions,,with 12 individuals included in each group.All the samples were then analyzed via 16 S r RNA sequencing,fluorescence quantification and non-targeted metabolomics to elucidate the difference in cecum microbiota and related metabolites.Comparison of the results of different developmental stages of Wenchang chickens revealed that the composition of intestinal microbiota plateaued with growth.The relative proportions of the dominant phyla,including Phylum Thick-walled,Phylum Bacteroidetes and Phylum Aspergillus,displayed stage-specific changes with development,indicating that gut microbiota and its metabolites may undergo structural and functional changes in different physiological states in response to nutritional metabolism and immune requirements.49 classes of differential microorganisms in total were detected among different developmental stages,while 253(27 vs 53d),349(53 vs 105d),360(105 vs133d),and 507(133 vs 161d)differential metabolites were detected between different adjacent stages,respectively.For example: Escherichia-Shigella 、 Acinetobacter 、Lactobacillus and so on.Analysis of difference among the local chicken varieties showed that the diversity of intestinal microbiota of free-ranged chickens was higher than that of caged chickens,indicating that free-range breeding is more effective in shaping the early microbiota of Wenchang chickens.These diversified microorganisms were still retained after the breeding of Wenchang chickens were converted from free-range to cage mode.19 classes of differential microorganisms among the three varieties,as well as 53(Danzhou chicken vs Sanhuang chicken),227(Sanhuang chicken vs Wenchang chicken)and 217(Wenchang chicken vs Danzhou chicken)differential metabolites between every two vatieties were detected,which were statistically different,and there was a correlation between differential microorganisms and metabolites.In depth analysis revealed that Bacteroidales and Prevotellaceae were significantly associated with metabolism of short-chain fatty acids such as butyric acid.In summary,these findings may provide new insights for studying the physiological and molecular mechanisms of developmental progress in the cecum microbiota of local chickens,resources for the identification of microorganisms and metabolites,as well as theoretical basis for improving poultry growth efficiency.