Hesham A Hassanien, Ahmed O Abbas, Fatma Mahsoub, Mohamed M El-Mekkawy
This study evaluates the effects of dietary presence of Vitex agnus-castus (VAC) oil on growth performance, gut microbiota, serum metabolic profile, immune response, inflammatory, carcass traits, and antioxidant status of broiler chickens. A total of 320 one-day-old, healthy Cobb chicks (initial BW = 49.5 ± 0.469 g) were randomly allotted into four dietary treatments: a basal control diet (VAC0) or diets supplemented with 0.25 (VAC0.25), 0.5 (VAC0.5), or 1.0 (VAC1.0) mL/kg of VAC oil over a 35-day period. GC-MS analysis identified 9,12-octadecadienoic acid (Z, Z)-, TMS derivative (30.24%), oleic acid, TMS derivative (19.55%), hexadecanoic acid, trimethylsilyl ester (12.98%), linolenic acid (8.37%), and 17-octadecynoic acid (6.8%) as the predominant bioactive components. Dietary VAC significantly increased final live body weight and total body weight gain in a quadratic pattern compared to the control (P < 0.01). Feed intake increased linearly with VAC inclusion, peaking at 0.5 and 1.0 mL/kg (P < 0.01). VAC supplementation quadratically reduced serum biomarkers of renal function (creatinine and urea) and hepatic injury (GGT, AST, ALT, and total/direct bilirubin; P < 0.01). Lipid profiles improved markedly, characterized by significant reductions in total cholesterol and triglycerides alongside elevated high-density lipoprotein (HDL) levels, particularly at 0.5 and 1.0 mL/kg (P < 0.01). All VAC doses quadratically enhanced antioxidant status by increasing SOD, TAC, and GPx activities, while suppressing oxidative damage markers (protein carbonyl and malondialdehyde; P < 0.01). Furthermore, VAC attenuated inflammation markers (lowering IFN-gamma and haptoglobin) and boosted humoral immunity via higher serum IgY and IgM concentrations (P < 0.01). Cecal microbial analysis revealed increased total bacterial counts alongside marked reductions in Escherichia coli and Clostridium spp. populations in all VAC groups (P < 0.01). In conclusion, VAC oil functions as a potent natural feed additive that enhances broiler performance, metabolic health, gut microflora, and antioxidant-immune defense, with 0.5 and 1.0 mL/kg identified as optimal dietary inclusion levels.