Performance, intestinal microbial population, immune and physiological responses of broiler chickens to diet with different levels of silver nanoparticles coated on zeolite

The aim of this study was to evaluate the effects of different levels of silver nanoparticles (Ag-NPs) coated on zeolite on performance, gastrointestinal microflora, heterophile to lymphocyte ratio and humoral immune system responses of broiler chickens. Three hundred seventy-five chicks (Cobb 500) in a completely randomised design were distributed to five diets: 1) basal diet, 2) basal diet containing 1% zeolite and 3, 4 and 5) basal diet containing 1% zeolite coated with 25, 50 and 75 ppm Ag-NPs. Performance traits were recorded and blood samples were taken to determine antibody response against Newcastle on day 14, infectious bursal disease on day 21 and serum immunoglobulins (Igs) were determined on day 42. Heterophile to lymphocyte ratio was evaluated on days 28, 35 and 42. The result showed that feed conversion ratio (FCR) was significantly decreased in Ag-NP treatments compared with control group (p < .05). Total anaerobic bacteria and the population of Escherichia coli in ileum and caecum were decreased (p < .05). The highest number of lactobacillus was observed in NS50 (p < .05). Antibody response against Gumboro was decreased as well as the amount of IgY antibody in Ag-NPs treatments. Significant differences were observed in heterophile to lymphocyte ratio on day 28 and 35 and the highest amount was observed in NS50 group (p < .05). In conclusion, although this study showed that using Ag-NP dietary coated on zeolite could improve gut microflora, but Ag-NPs could also have side effects on the immune mechanism of broiler chickens.Highlights Silver nanoparticles (Ag-NPs) coated on zeolite improved feed efficiency at different levels. Ag-NPs (50 ppm) coated on zeolite reduced Escherichia coli number and decreased lactobacillus number. Ag-NPs (50 ppm) coated on zeolite decreased antibody response against Gumboro and amount of IgY antibodies.