Previously, the supplementation of a microencapsulated blend of organic acids and botanicals improved the health and performance of broiler breeders under non-challenged conditions. This study aimed to determine if the microencapsulated blend impacted dysbiosis and necrotic enteritis (NE) in broiler breeders. Day-of-hatch chicks were assigned to non-challenge and challenge groups, provided a basal diet supplemented with 0 or 500 g/MT of the blend, and subjected to a laboratory model for NE. On d 20-21, jejunum/ileum content were collected for microbiome sequencing (n = 10; V4 region of 16S rRNA gene). The experiment was repeated (n = 3), and data were analyzed in QIIME2 and R. Alpha and beta diversity, core microbiome, and compositional differences were determined (significance at p ≤ 0.05; Q ≤ 0.05). There was no difference between richness and evenness of those fed diets containing 0 and 500 g/MT microencapsulated blend, but differences were seen between the non-challenged and challenged groups. Beta diversity of the 0 and 500 g/MT non-challenged groups differed, but no differences existed between the NE-challenged groups. The core microbiome of those fed 500 g/MT similarly consisted of Lactobacillus and Clostridiaceae. Furthermore, challenged birds fed diets containing 500 g/MT had a higher abundance of significantly different phyla, namely, Actinobacteriota, Bacteroidota, and Verrucomicrobiota, than the 0 g/MT challenged group. Dietary supplementation of a microencapsulated blend shifted the microbiome by supporting beneficial and core taxa.
Keywords: Clostridium perfringens; feed additive; microbiome; microencapsulated organic acids and botanicals; necrotic enteritis.