Application of nano-selenium as a dietary supplement and its effects on antioxidant status and gene expression related to oxidative stress in broiler chickens

Background: Antioxidants are important factors in reducing stress on poultry birds. Recently, nanomaterials have been introduced as part of feed additives to enhance the health of birds. Aim: This study aimed to evaluate the effects of dietary Nano-Se supplementation on broiler chicken growth performance, serum antioxidant status, and hepatic expression of oxidative stress-related genes. In total, 250 one-day-old Ross 308 broiler chicks were reared for up to 42 days. Methods: Birds were randomly assigned to five treatments (n = 50 birds/treatment; 5 replicates of 10 birds each) in a completely randomized design as follows: 1st treatment (T1; basal diet, control), 2nd treatment (T2; basal diet + 0.3 mg/kg organic Se), 3rd treatment (T3; basal diet + 0.3 mg/kg Nano-Se), 4th treatment (T4; basal diet + 0.6 mg/kg Nano-Se), and 5th treatment (T5; basal diet + 0.9 mg/kg Nano-Se). Results: Growth performance was recorded weekly. On day 42 , blood samples were collected for biochemical analysis of antioxidant enzymes, including GPx, SOD, TAC, and MDA. Liver tissue was harvested for quantitative real-time PCR analysis of GPX1, SOD1, CAT, Nrf2, and HO-1 gene expression. T4 showed a significant improvement in the final weight and feed conversion ratio. A significant increase in serum GPx activity was observed for T4 compared to T1 at 59.6% (125.3 vs. 78.5 U/mL;P