In vitro growth of gut microbiota with selenium nanoparticles

The application of nanoparticles rose steeply in the last decade,where they have become a common ingredient used in processed human food,improving food properties such as shelf life and appearance.Nanoparticles have also attracted considerable interest to the livestock industry,due to their efficacy in intestinal pathogen control,with the regulatory and consumer driven push for the removal of antibiotic growth promoters.The influence of selenium(Se) nanoparticles was investigated on a diverse and mature broiler caecal microbiota using in vitro culturing and 16 S rRNA gene sequencing methods for microbiota characterisation.Caecal microbiota was collected from 4 traditionally grown heritage roosters and grown for 48 h,in the presence and absence of Se nanoparticles,with 2 technical replicates each.The effect of rooster as a biological variable strongly overpowered the effects of nano-Se in the media,resulting in moderate effects on the structure and diversity of the caecal microbial community.However the nanoparticles showed a significant reduction(P <0.05) in the abundance of an emerging poultry pathogen,Enterococcus cecorum identical operational taxonomic units(OTU),which could be of notable interest in poultry production for targeted E.cecorum control without significant disturbance to the total microbial community.

The temporal fluctuations and development of faecal microbiota in commercial layer flocks

The microbiota of the gastrointestinal tract influences gut health,which in turn strongly impacts the general health and productivity of laying hens.It is essential to characterise the composition and temporal development of the gut microbiota in healthy layers raised under different management systems,to understand the variations in typical healthy microbiota structure,so that deviations from this might be recognised and correlated with production and health issues when they arise.The present investigation aimed to study the temporal development and phylogenetic composition of the gut microbiota of four commercially raised layer flocks from hatch to end of the production cycle.Non-intrusive faecal sampling was undertaken as a proxy to represent the gut microbiota.Sequencing of 16S rRNA gene amplicons was used to characterise the microbiota.Beta diversity analysis indicated that each faecal microbiota was different across the four flocks and had subtly different temporal development patterns.Despite these inter-flock differences,common patterns of microbiota development were identified.Firmicutes and Proteobacteria were dominant at an early age in all flocks.The microbiota developed gradually during the rearing phase;richness and diversity increased after 42 d of age and then underwent significant changes in composition after the shift to the production farms,with Bacteroidota becoming more dominant in older birds.By developing a more profound knowledge of normal microbiota development in layers,opportunities to harness the microbiota to aid in the management of layer gut health and productivity may be more clearly seen and realised.