Abstract
The current study was conducted to study the effects of dietary zinc oxide nanoparticles (ZnONPs) supplementation on broiler’s performance, immune response, some hematological, biochemical and histopathological changes. A total of 100 one-day-old Ross (308) broiler chicks were randomly divided into two dietary treatments (50 chicks per each) the first group fed on the basal diet without any supplement, the second group chicks treated with 20mg ZnONPs /kg diet. The chicks received the treatment daily for 37 successive days. The obtained results clarified that ZnONPs supplementation significantly (P<0.05) improved final body weight, weight gain and average FCR throughout the whole experimental period by about 5.5%, 5.6% and 3.5% respectively and increased PCV values, Hb content, WBCs count, serum total protein, serum albumin and globulin concentrations while, reduced serum cholesterol and triglycerides levels at 3rd and 5th weeks of age compared to control. Moreover, it was indicated that ZnONPs supplementation increased (P˂0.05) phagocytic activity by about 36.5% and exhibited significantly higher bursa and thymus gland relative weights at 3rd or 5th weeks of broiler chickens age compared to the control. Intestinal villi of the treated group showed significant improvement in length, width, goblet cell number and crypt depth in comparison with the control group at 3 and 5 weeks of the experiment. Liver, kidney and spleen of treated chicks showed normal histological structures the same as the control chicks. In conclusion, the dietary inclusion of ZnONPs improved the growth, performance and immune response in broiler chicks. So, we recommended its use in poultry farms as its growth promoting and immuno-stimulant effects.

Key words: Broilers, zinc oxide nanoparticles, growth performance, immune response, serum biochemical and histopathology.