Effects of supplemented oregano on the maturation of broiler faecal microbiota

Oregano-based products are being increasingly used in livestock feed as a replacement for antibiotics. Despite the increasing use of oregano on poultry farms, little is known about the influence it may have on the development of the intestinal microbiota of chickens, especially when used from first days of life. We investigated the effect of oregano supplementation in the development of intestinal microbiota in Ross 308 broilers grown with and without 2% oregano in the feed. Faecal samples were collected weekly from week 1 to week 6, and microbial communities were investigated via sequencing of 16S rRNA gene amplicons. Linear regression based on Pearson’s correlation showed no difference in taxa positively or negatively correlated with the timeline, in either known pathogenic or beneficial genera, despite some taxa identified as differentially abundant (P < 0.05) between control and oregano treatments. The results we present question the validity of using faecal samples to pinpoint slight differences in microbiota.