This experiment was conducted to evaluate the effects of different levels of nanosilicon dioxide (nSiO2) on performance, egg quality, liver histopathology and concentration of calcium (Ca), phosphorus and silicon (Si) in egg, liver and bone in laying quails. The experiment was administered using 60 laying quails at 16–26 weeks of age with five treatments [0 (control), 500, 1000, 2000 and 4000 mg nSiO2 per kg of diet] and four replicates in a completely randomized design. During the experiment, the amount of feed intake was recorded weekly and performance parameters were measured. During the last 3 days of the experiment, all of the eggs in each replicate were collected and egg quality parameters were measured. At the end of 26 weeks of age, the birds were sacrificed and blood samples were collected. Liver samples from each treatment were fixed in 10% buffered formalin for histopathological assessment. The right thigh bone and a portion of liver were inserted in plastic bags and stored at − 20. The results showed that nSiO2 supplementation significantly affected egg weight and egg mass (P < 0.05). Also, dietary nSiO2 supplementation decreased the yolk weight and increased the shell weight (P < 0.05). Moreover, nSiO2 increased bone ash content, Ca and Si concentration in the bone (P < 0.05). The liver enzymes in plasma and the liver tissue histopathology were not significantly affected (P > 0.05) by dietary treatments. In conclusion, the results indicated that dietary supplementation of nSiO2 could improve bone density and performance without any adverse effect on the health of laying quails.
