In commercial production settings, broilers are exposed to numerous environmental and immunological stressors. In this study, two commercial feed additives (Micro-Aid® Feed Grade Concentrate and Micro-ShieldTM; DPI Global, Porterville, CA) were evaluated for their effects on growth performance, antioxidant defenses, and intestinal health. A total of 420 male Ross 708 chicks at 2 d post-hatch were assigned to 1 of 5 treatment groups with 7 birds allotted to each of the 12 replicate cages. The 42-d study (starter d 0-14, grower d 14-28, finisher d 28-42) was conducted with treatments including 1) control diet fed to birds not exposed to stressors (NC), 2) control diet fed birds exposed to stressors (PC), 3) PC + 500 mg of Micro-Shield/kg of diet in the starter phase only (MS), 4) PC + 500 mg of Micro-Shield/kg diet in the starter, grower, and finisher phases (MSall), and 5) PC + 500 mg of Micro-Shield/kg diet in the starter phase + 250 mg of Micro- Aid/kg diet in the grower and finisher phases (MS+MA). To achieve a multiple mild stressors challenge, birds underwent a 12- h feed withdrawal prior to a coccidiosis vaccine challenge on d 15 of the study, which was designated as 0 d post-inoculation (DPI). Additionally, birds were exposed to cyclic elevated brooder temperatures during the grower phase. All data were subjected to a 1-way ANOVA using the MIXED procedure of SAS with results considered significant when P < 0.05. Birds exposed to stressors had lower BWG, lower FI, and a poorer FCR during the grower phase compared with birds in the NC group (P < 0.05). On DPI 6, birds in the MS+MA treatment had the highest (P < 0.05) levels of catalase in blood serum, potentially indicating higher antioxidant capacity. On DPI 13, IL-1β and IL-10 gene expression was highest (P< 0.05) in the MS+MA and MSall treatment groups, respectively, indicating that Micro-Aid and Micro-Shield may have immunomodulatory effects in coccidiosis-infected birds. While birds in the NC treatment had the highest gene expression of ZO-1 in jejunal mucosa tissue on DPI 6 (P < 0.05), MS+MA birds had similar ZO-1 expression compared with NC birds. Overall, these results suggest Micro-Aid and Micro-Shield may confer health benefits onto birds experiencing environmental and immunological stressors.

Froebel, L., M. Rincker and R. Dilger. 2025. Evaluation of botanical feed additives rich in saponins and polyphenols in broilers experiencing immunological and environmental stressors. 2025 International Poultry Scientific Forum, Abstract M124.