Effect of Chromium Nanoparticles on Physiological Stress Induced by Exogenous Dexamethasone in Japanese Quails.

Chromium (Cr), as an essential trace element, plays a critical role in carbohydrate, protein, and lipid metabolism in animals. It has been suggested that the beneficial effects of Cr increase by environmental stresses, which lead to greater Cr effects on stressed animals. The objective of the present study was to evaluate the response of physiologically stressed Japanese quails (Coturnix japonica) to dietary chromium nanoparticle (Nano-Cr) supplementation. The stress was induced by adding dexamethasone (0.6 mg/kg BW) to Japanese quails' diet from 17 to 22 days of age. A total of 360 birds were randomly allocated to six dietary treatments with four replicates each having 15 birds: negative control diet (no-stress, no-additive; NC), positive control diet (stress, no-additive; PC), and stress additive diets including four diets containing 200, 400, 800, and 1200 μg/kg of Nano-Cr. Performance and haematological parameters were affected (P < 0.05) by physiological stress though they were not affected by adding Nano-Cr. Comparison of diets containing Nano-Cr levels and stress no-additive diets, at 23 days of age, was indicative of a positive linear relationship (P < 0.05) between dietary Nano-Cr levels and feed intake and average daily gain. Furthermore, white blood cell (WBC) count as well as haematocrit level increased (P < 0.05) as the level of supplied Nano-Cr increased. A negative relationship (P < 0.05) was observed between Nano-Cr levels and heterophil percentage and heterophil/lymphocyte ratio. On day 35, increased dietary Nano-Cr improved (P < 0.05) weight gain, live body weight, energy/protein utilization efficiency, and WBC count. In conclusion, supplementation of diet with optimum concentration of Nano-Cr revealed alleviation of negative effects of physiological stress in quails.