Dietary palygorskite supplementation improves immunity, oxidative status, intestinal integrity, and barrier function of broilers at early age

The current study was conducted to investigate the effects of palygorskite inclusion in diet on the immunity, oxidative status, intestinal integrity, and barrier function of broilers at early age. A total of 144 one-day-old Arbor Acres broiler chicks were allocated into 3 dietary treatments with 6 replicates of 8 chicks each, and fed a basal diet supplemented with 0, 5 and 10 g/kg palygorskite for 21 days, respectively. Treatments did not alter the growth performance of broilers. Compared with the control group, the inclusion of 10 g/kg palygorskite decreased serum diamine oxidase (DAO) activity (P = 0.041). Dietary palygorskite supplementation increased ileal goblet cell number (P = 0.004), and the ratio of villus height to crypt depth in the jejunum (P < 0.001) and ileum (P = 0.001), and the extent to increase the ratio of villus height to crypt depth in jejunum was more pronounced when its dosage was 10 g/kg (P < 0.05). Similarly, broilers fed a diet supplemented with 10 g/kg palygorskite exhibited increased jejunal goblet cell number (P = 0.021), and villus height in the jejunum (P = 0.002) and ileum (P = 0.008). Palygorskite supplementation, irrespective of dosage, reduced cecal Salmonella colonies (P = 0.038). Dietary 10 g/kg palygorskite supplementation increased the concentrations of ileal immunoglobulin M (IgM, P = 0.037) and secretory immunoglobulin A (SIgA, P = 0.023), and the activity of total superoxide dismutase (T-SOD) in the jejunum (P = 0.035) and ileum (P = 0.049). The inclusion of 10 g/kg palygorskite increased mRNA abundances of ileal mucin 2 (MUC2, P = 0.033) and zonula occludens-1 (ZO-1, P = 0.017) whereas reduced mRNA expressions of ileal toll-like receptor 4 (TLR4, P = 0.040) and interferon-γ (IFN-γ, P = 0.023). Additionally, the supplementation of 5 g/kg palygorskite increased jejunal trefoil factor 2 (TFF2) mRNA abundance (P = 0.042), but downregulated the expression of ileal IFN-γ mRNA (P = 0.023). In conclusion, dietary palygorskite inclusion would exert beneficial effects on the immunity, antioxidant capacity, intestinal integrity, and barrier function of broilers at early age.