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.