Dietary Influence of Scent Leaf (Ocimum sanctum) and Bitter Leaf (Vernonia amygdalina) Meals as Modulators of Oxidative Stress and Immune Response in Broiler Chickens

Abstract

Oxidative stress and altered immune responses can affect the health and productivity of intensively reared broiler chickens. This study evaluated dietary bitter leaf meal (BLM; Vernonia amygdalina), scent leaf meal (SLM; Ocimum sanctum), and their combination as phytogenic supplements affecting serum immune and antioxidant indices in broilers. Two hundred and fifty one-day-old unsexed Arbor Acres broiler chicks were randomly assigned to five dietary treatments, with five replicates of ten birds. The treatments comprised a vaccinated and medicated positive control, an unsupplemented negative control, 0.3% BLM, 2% SLM, and a combination of 0.3% BLM and 2% SLM. On day 21, serum samples were evaluated for cytokines, immunoglobulin A, total protein, oxidative stress markers, and antioxidant enzyme activities. Dietary treatment significantly affected interferon-gamma, interleukin-1β, interleukin-4, interleukin-10, catalase, glutathione peroxidase, and total protein. Birds receiving 2% SLM recorded the highest interferon-gamma (60.39 pg/mL), interleukin-4 (205.84 pg/mL), and interleukin-10 (25.64 pg/mL) concentrations. Immunoglobulin A did not differ significantly among treatments (P = 0.193), although the highest numerical value was recorded with 2% SLM. Total antioxidant capacity also did not differ significantly, but the combined 0.3% BLM and 2% SLM treatment produced the highest numerical value (13.37 mmol/L). These findings indicate that scent and bitter leaf meals influenced selected immune and antioxidant indices in broiler chickens under the conditions of this 21-day study.