This study aimed to evaluate the effects of dietary supplementation of nanoparticles of Selenium (Nano-Se) on productive performance, nutrient digestibility, carcass criteria, selenium retention, blood biochemistry, and histopathological examination of broiler chicken. A total of 192 1-day-old male broiler chickens (Cobb 500) were randomly assigned to one of four treatment diets, with each diet given to six replicates of eight chicks. The birds were randomly assigned to one of four treatment groups, each of which included Nano-Se at levels of 0, 0.2, 0.3, or 0.4 mg/kg. The feeding experiment lasted 35 days. Nano-Se addition to broiler diets at 0.2 and 0.3 mg/kg enhanced body weight and body weight gain linearly compared to the control diet and 0.4 mg/kg. The apparent digestibility coefficient of ether extracts linearly increased with increasing Nano-Se levels up to 0.4 mg/kg. Increasing Nano-Se decreased serum cholesterol, triglycerides, alanine aminotransaminase, aspartate aminotransaminase, and creatinine in broiler chickens. Also, serum antioxidants showed a significant increase with increasing Nano-Se levels. As Nano-Se levels were supplemented, improvements in cooking loss, water-holding capacity, and antioxidants were observed as compared to the control. Additionally, a noticeable improvement in meat quality was observed regarding the obtained meat characters. It was preferred to use low doses of Nano-Se (0.3 mg/kg), as tissue retention of Se for both meat and liver was more comparable to the control. In conclusion, nutritional supplementation with Nano-Se increased growth performance, nutrient digestibility, selenium retention, meat quality, blood biochemistry, histological indices, and antioxidant activity of broiler chickens. Overall, the best performance of broilers was observed with Nano-Se supplementation at 0.3 mg/kg, highlighting its potential as a novel supplement for broiler diets.
