Enhancing immune response in broiler chicks against newcastle disease virus using lemongrass and geranium oils: A comprehensive study on biochemical and antioxidant effects

This study evaluated the effects of lemongrass oils (LO) and geranium oils (GO) on the immune response to NDV in 250 one-day-old Cobb broiler chicks. The chicks were divided into vaccinated and non-vaccinated groups, each further split into eight subgroups receiving LO, GO, or both as prophylactic or treatments post-NDV challenge. Mortality rates increased in treated non-vaccinated groups to 80 % (vs. 53.3 % in controls) and 20 % in vaccinated groups (vs. 13.3 % in controls). Biochemically, LO and GO improved liver and kidney function markers, including reduced serum ALT, AST, creatinine, and MDA, alongside a two-fold increase in spleen antioxidant Nuclear factor erythroid 2–related factor 2 (Nrf2) levels. Immune modulation showed elevated interleukin-10 (IL-10) and reduced interferon-gamma (IFN-γ) expression, indicating enhanced anti-inflammatory responses but potentially dampened antiviral immunity. Antibody titers against NDV increased significantly in non-vaccinated treated groups, suggesting improved viral resistance, whereas vaccinated groups showed minimal changes. Despite the observed biochemical and immune benefits, the unexpected rise in mortality underscores a complex interaction between LO, GO, and NDV, warranting further investigation into their mechanisms and safety. This study highlights the potential of LO and GO as natural immunomodulators but emphasizes the need for optimized dosing and application protocols to minimize adverse effects.