Synergistic effects of zinc oxide and selenium nanoparticles in drinking water on broiler chicken growth, antioxidant, and immunity responses

The poultry sector faces several nutritional and health challenges, including deficiencies in essential micronutrients such as zinc and selenium, which, although required in low levels, are important for growth and immune function. Nanotechnology has emerged as a promising tool to enhance nutrient bioavailability and efficacy. While individual benefits of Zn and Se nanoparticles (NPs) have been demonstrated, research on their combined effects in broilers is limited. In this study, we aimed to evaluate the effects of combined zinc oxide (ZnO) and Se NPs in drinking water on the performance, gut morphology, antioxidant capacity, and humoral immunity of broiler chickens. A total of 252 one-day-old chicks were randomly assigned for 35 days to six treatment groups, each consisting of six replicates with seven birds per experimental cage. The treatments included a negative control (T1) without Zn and Se supplementation, a positive control (T2) with inorganic Zn and Se supplementation, and four treatments (T3, T4, T5, and T6) receiving combined ZnO and Se NPs at doses of 35 and 0.15, 70 and 0.3, 35 and 0.3, and 70 and 0.15 mg/L, respectively. Birds receiving combinations of ZnO and Se NPs demonstrated significant improvements in body weight, feed efficiency, and feed intake. Enhanced villus height in the small intestine, increased antioxidant enzyme activities, and reduced malondialdehyde levels were also observed. Antibody titres against Newcastle disease virus were significantly elevated. In conclusion, combined ZnO and Se NPs can enhance growth, physiological status, and immune function in broiler chickens.