The persistence and dynamics of commensal poultry gut flora within a broiler rearing house

Commercial poultry rearing systems often house successive flocks of birds with limited between-flock cleaning of the poultry houses. Previous research focused on opportunities for successive flocks to become colonised with pathogenic bacterial species. However, there is a paucity of information regarding the transfer and persistence of commensal bacterial between flocks, and if this might confer health benefits on subsequent flocks. The work presented here utilised 16S community sequencing to characterise the development of the microbial flora of commercially reared broiler chickens and turkeys to determine microbial environmental persistence. DNA was isolated from caecal contents, faeces, and various bedding samples collected from nine sites over a nine month period. Samples were taken from houses used for rearing chickens or turkeys or where alternating chicken and turkey flocks were reared. Measures of alpha diversity for the different samples suggested that both chickens and turkeys had a similar microbiota. Unsurprisingly, members of the microflora could also be found in the environmental samples tested, although survival was dependent on the phyla and bedding material. Further analysis of the samples is currently underway, in order to determine the extent, if any, of microbial transfer between flocks, with a particular focus on potential poultry microbiota species differences. This study demonstrated how commensal microbes are able to persist within poultry rearing sheds and if this transfer impacts on subsequent flock performance. Alongside increasing understanding of microbial environmental persistence, the work also shows how effective current biosecurity methods are in controlling the transfer of all microbes, including pathogens.