Tenebrio molitor and Zophobas morio full-fat meals as functional feed additives affect broiler chickens' growth performance and immune system traits

This study was conducted to investigate the effect of insect full-fat meals (Tenebrio molitor and Zophobas morio larvae), added on top of a complete diet or calculated into diets, on the growth performance, selected blood, and immune system traits of broiler chickens. 1,000 one-day-old female Ross 308 broiler chicks were used in 2 independent experiments. In the first trial, the birds were randomly assigned to 6 treatments, 10 replicate pens per treatment, and 10 birds per pen, i.e., negative control; positive control with salinomycin addition (60 mg/kg diet), and addition of 0.2% and 0.3% of T. molitor and Z. morio full-fat meals on top. In the second experiment, 4 treatments, 10 replicate pens per treatment, and 10 birds per pen were set, i.e., negative control, positive control with salinomycin addition (60 mg/kg diet), and 0.3% of T. molitor and Z. morio full-fat meals calculated in the diets. In both trials the supplementation of insects increased the BWG (Exp. 1: P = 0.024; Exp. 2: P = 0.046) and FI (Exp. 1: P = 0.022; Exp. 2: P = 0.026), and no negative effect on the FCR was recorded in experiment one (P = 0.514), however in second trial insects addition increased FCR values (P = 0.011). In addition, in the first trial, groups fed insects and PC comparing to NC decreased the IgY (P = 0.045) and IgM, (P < 0.001) levels. In the second experiment, IgM levels were also decreased (P < 0.001) in groups fed insects comparing to NC. Moreover, in first trial the IgM levels were negatively correlated to the BWG (r = -0.4845) and FI (r = -0.4986), with statistically significant values (P < 0.001). In conclusion, the current results confirmed that small amount addition (0.2% and 0.3%) of T. molitor and Z. morio full-fat meals to the diet of broiler chickens can improve growth performance and change selected the immune system traits.