Protective effects of nano-zinc and nano-selenium compared with a toxin binder in broiler chickens fed aflatoxin B1-contaminated diets through antioxidant, immune, and skeletal responses

Aflatoxin B1 (AFB1) can impair broiler performance, redox balance, and skeletal health. This 42-day study evaluated whether partial replacement of conventional inorganic zinc (Zn) and selenium (Se) sources with nanoforms could mitigate AFB1-associated responses and compared this source-substitution strategy with the use of commercial toxin binder. A total of 792 day-old male Ross 308 broilers were allocated to six treatments (6 replicate pens/treatment, 22 birds/pen; pen served as the experimental unit): Control; AF (0.5 mg AFB1/kg); AF+TB (2 g toxin binder/kg); AF+NZ (40 mg Zn/kg supplied as nano-zinc in place of an equivalent amount from zinc sulfate); AF+NS (0.1 mg Se/kg supplied as nano-selenium in place of an equivalent amount from sodium selenite); and AF+NZ+NS (combined nano-Zn and nano-Se partial replacement). Supplemental Zn and Se were maintained at 120 and 0.3 mg/kg, respectively. Relative to AF, AF+TB and AF+NZ+NS increased body weight gain by 9.7% and 6.3%, feed efficiency by 6.8% and 5.7%, total antioxidant capacity by 37.6% and 34.5%, and serum GSH by 38.6% and 35.7%, respectively, while reducing serum MDA by 31.0% and 32.1% (P < 0.05). Both treatments also improved selected immunoglobulin measures, hepatic expression of NFE2L2, GPX1, and SOD1, culture-based bacterial counts, tibial length and tibia ash content, although AF+NZ+NS did not consistently outperform the single nano-mineral treatments and did not fully restore the control phenotype. Under the conditions of this 42-day, 0.5 mg/kg AFB1 challenge, combined partial replacement with nano-Zn and nano-Se improved several measured responses, including productive performance, antioxidant status, and tibia quality.