Supplementing a Herbal Product (NBS Superfood) in Broiler Diets Varying in Energy and Protein Levels: Effects on Growth Performance, Intestinal Morphology, Immune Response and Blood Metabolites

This study aimed to evaluate the effects of dietary supplementation of nutrition bio-shield superfood® (nbs) on the growth performance, intestinal morphology, immune response and blood metabolites in broiler chickens fed with low metabolizable energy (me) and crude protein (cp) diets. a total of 360 one-day-old ross 308 broilers were used in a 42-d experiment. the birds were allotted to 6 dietary treatments with 5 floor pen replicates of 12 birds each; based on a completely randomized design. dietary treatments included a positive control diet (pc, standard diet), a negative control diet (nc, 3% reduction in me and cp without nbs supplementation), and dietary supplementation of nbs at 0.5, 1, 1.5, and 2 g/kg to negative control diet (nbs0.5, nbs1, nbs1.5, nbs2, respectively). body weight on d 10 and body weight gain during d 1-10 were lower (p < 0.05) in birds fed with nc and nbs diets compared to the positive control group. during later phases and d 1-42, no significant differences were observed in body weight, body weight gain, feed intake, and feed conversion ratio of broilers among the treatments. supplementation of nbs or lowering the nutrients by 3% had no significant effect on immune response (total ig, igg and igm concentrations) compared to positive control group. nbs supplementation decreased muscle layer thickness (mlt) in the jejunum (p < 0.01). villus width (wv) and mlt showed a linear response to the treatments (p = 0.02 and p = 0.02, respectively), in this case, vw increased with the supplementation of nbs at 0.5 to 2 g/kg, and mlt decreased with these levels of dietary nbs. in general, dilution of nutrients by 3% of the standard diet and dietary supplementation of nbs had no significant effect on growth performance, immune response, blood metabolites and carcass traits in broiler chickens.