Chitosan nanoparticles administration improves immune function, serum digestive enzyme levels and selected cecal bacterial populations in broiler chickens

A total of 400 one-day-old male Ross 308 broiler chickens were randomly allocated into four treatments with five replicate pens, each containing 20 broilers, for a 42-day experimental period. The experimental diets were as follows: the first group was fed a basal diet only (control); the 2nd, 3rd and 4th groups received a basal diet supplemented with chitosan nanoparticles (ChNPs) at: 50 (ChNPs-50), 100 (ChNPs-100) and 150 (ChNPs-150) mg ChNPs/kg of feed, respectively. At the end of the experiment, 10 birds from each dietary treatment were randomly selected for sample collection. Serum amylase and lipase activities were significantly increased by ChNPs supplementation at 150 mg/kg compared with the control group. Dietary supplementation with ChNPs exerted antioxidant effects in broiler chickens, primarily through increased superoxide dismutase (SOD) activity and reduced malondialdehyde (MDA) levels, although glutathione peroxidase (GPx) activity was not significantly affected. Humoral immunity (immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM]) and anti-inflammatory interleukin-10 (IL-10) increased, while pro-inflammatory cytokines (interleukin-1β (IL-1β), interleukin-6 (IL-6) decreased at 100–150 mg/kg. Cecal bacterial populations were altered, with increased Lactobacillus spp. and decreased E. coli counts. Overall, ChNPs at 100–150 mg/kg enhanced immune responses and altered selected cecal bacterial populations, with dose-related increases in SOD activity and reductions in MDA concentrations.