PSXVI-2 - Response of ileal microbiota composition and immunity function to xylanase supplementation in broilers fed wheat-based diets

A total of 112 one-day-old broilers (initial BW 48.03 ± 0.33 g) were selected to investigate effects of xylanase (AT-xynA) on growth performance, ileal morphology, microbiota composition, immune response, antioxidant capacity and endocrine peptide levels in broilers [Founded by NSFC (31772612)]. Broilers were randomly allotted into 2 dietary treatments (n = 7) including a wheat-soybean basal diet (CON), and a basal diet with 4,000 U/kg AT-xynA (XY). On d 7, 14, 21 and 42, broilers were weighted and ileal tissues were sampled. Ileal digesta samples were collected for analyzing microbiota composition on d 21 and 42. The results showed that AT-xynA could improve average daily weight gain and average daily feed intake, and there were interactions between diet and age of broilers (P < 0.05). On d 21 and 42, xylanase supplementation could decrease ileal microbiota α-diversity, the relative abundance of potentially pathogenic microbiota such as phyla Proteobacteria, family Moraxellaceae, Staphylococcaceae, genus Staphylococcus, Pseudomonas, Streptococcus, Enterococcus, and increased the abundance of Lactobacillus (P < 0.05). Moreover, the reduction in acetate concentration and abundance of short chain fatty acid producing bacteria was also observed in broilers from XY group (P < 0.05). AT-xynA could increase ileal villus height, glucagon-like peptide-1 and insulin-like growth factor-1 concentrations, decreased interleukin-1β, interleukin-6, tumor necrosis factor‐α and malondialdehyde content in broilers from XY group, and these positive effects on intestinal health were greater in young broilers. In conclusion, xylanase supplementation to wheat-based diets could improve intestinal health, and the positive effects of xylanase supplementation were more pronounced in young broilers, thus contributing to subsequent improvements in growth performance of broilers.