Novel in ovo application of green-synthesized Fe3O4, Cu, and ZnO nanoparticles: enhancing early growth and physiological responses in Domiaty ducks

Abstract Enhancing embryonic nutrient utilization is a key strategy for improving the early growth and health of poultry. This study investigated the effects of in ovo injection (30 µg/egg) of green-synthesized iron oxide nanoparticles (Fe 3 O 4 -NPs), copper nanoparticles (Cu-NPs), and zinc oxide nanoparticles (ZnO-NPs) on the early growth performance, physiological responses, antioxidant status, and intestinal morphology of Domiaty ducklings. The nanoparticles (NPs) were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and zeta potential analyses, confirming their spherical morphology, nanoscale size (2–16 nm), and good stability. A total of 450 fertile duck eggs were assigned to five groups: non-injected control, saline-injected control, and three NPs-treated groups. In ovo administration was performed on the 14th embryonic day (ED). The results showed significant improvements in hatchling body weight and 7-day post-hatch growth in all NPs-treated groups, with Fe 3 O 4 -NPs and ZnO-NPs producing the greatest responses. Serum lipid profiles showed favorable changes, with reduced cholesterol, triglyceride (TG), and low-density lipoprotein (LDL) levels, and increased high-density lipoprotein (HDL) levels. Hemoglobin (Hb), transferrin (Tf), thyroid hormones (T3 and T4), IgG levels, and antioxidant indicators, such as total antioxidant capacity (TAC), superoxide dismutase (SOD), and glutathione (GSH), were enhanced, whereas malondialdehyde (MDA) levels were reduced. Histological examination revealed improved jejunal villus development and crypt architecture. In general, the findings reveal that in ovo administration of biosynthesized metal NPs may positively influence early growth, selected physiological and immune-related traits, antioxidant status, and intestinal development in Domiaty ducks.