This experiment was conducted to evaluate the influence of different sources of Cr on growth performance, economical efficiency and blood constituents in heat-stressed Japanese quails. A total of 280 Japanese quails at 2 weeks of age were distributed into four groups with seven replicates (10 in each). The quails were kept under heat stress conditions (34.1 ºC temperature and 41.7% relative humidity) during the day light between 14 and 49 days of age. The first group fed basal diet without supplementation and saved as control group, while the 2nd, 3rdand 4th groups were fed basal diet supplemented with 200 ppm/kg diet of Cr chloride (CrCl3), chromium yeast (Cr-Yeast) or chromium picolinate (Cr-Pic), respectively. Body weight and feed intake were recorded. Body weight gain, feed conversion ratio, production index and economical efficiency were calculated.
The results showed that chromium supplementation improved BWG, FCR, carcass percentage, economical efficiency, production index, nutrient digestibility and antioxidant properties and decreased abdominal fat. Fed Japanese quails on diet supplemented with Cr-Pic resulted in the greatest BWG, FCR, economical efficiency and production index followed by those fed basal diet supplemented with Cr-yeast then CrCl3. Chromium administration significantly reduced plasma glucose, triglycerides, total cholesterol and LDL and increased HDL. Plasma total protein levels increased due to inclusion of Cr-Pic or Cr-Yeast into chick diets. Different sources of Cr supplementation significantly increased Lymphocytes and decreased Heterophile /Lymphocytes ratio than the control group. It can be concluded that chromium (either organic or inorganic) supplementation to diet had a beneficial effect on productive performance, economical efficiency and production index of Japanese quails. However, Japanese quails on diet supplemented with Cr-Pic resulted in the greatest productive performance, economical efficiency and production index followed by those fed basal diet supplemented with Cr-yeast then CrCl3.