Lack of consistency in poultry dust microbial taxa associated with high and low-performing commercial broiler flocks.

The microbial communities of the gastrointestinal tract play an essential role in poultry health and productivity. Poultry dust has been used to investigate bacterial taxa associated with performance in commercial broiler farms. This study investigated the commonalities of poultry dust microbial taxa associated with performance in samples collected from three broiler integrator companies and their stability in a successive flock of the same companies using deep sequencing of the 16S rRNA gene. Poultry dust samples (n = 248) were collected on days 14 and 35 of the production cycle from 38 commercial broiler flocks (2 flocks from each of 19 farms). The farms were ranked as low or high performers based on the feed conversion ratio corrected for body weight. Permutational analysis of variance based on Bray-Curtis index using abundance data for bacterial community structure results showed that company explained the most variation in the bacterial community structure (7.5 %), followed by bird age (2 %) and the least variation was explained by performance (1.9 %), with significant interactions among these factors (P < 0.001). No bacterial taxa in high or low-performing farms overlapped in all three companies or successive flocks from the same company. Some taxa associated with high performance in a company were associated with low performance in another company (e.g., Bifidobacterium), corroborating other studies highlighting the lack of universal microbial markers of productivity. In conclusion, there were no consistent microbial taxa across companies and flocks within a company under the conditions of this study.