Dietary Sodium and Chloride for Twenty-Nine-to Forty-Two-Day-Old Broiler Chickens at Constant Electrolyte Balance Under Subtropical Summer Conditions

SUMMARY The study was conducted to evaluate the response of broiler chicks to different dietary Na + and Cl − concentrations with similar dietary electrolyte balance of 250 mEq/kg during 29 to 42 d of age in a hot environment with average minimum and maximum temperatures of 32.4 and 36.6°C, respectively, and an average RH of 69.2%. Three levels of dietary Na + (0.20, 0.25, and 0.30%) and 3 levels of dietary Cl − (0.30, 0.40, and 0.50%) were used in 3 × 3 factorial arrangement in which BW at 28 d were used as covariate in the statistical analysis. A decreasing linear effect of dietary Na + was observed on breast yield and lowering of abdominal fat, whereas increasing dietary Cl − linearly increased litter moisture and decreased dressing weights. No significant effects of dietary Na + ,C l − ,o r Na + × Cl − were observed on feed intake, BW gain, feed:gain, rectal temperature, water:feed, or mortality. An improvement in litter condition, toe ash, blood parameters, and lowered abdominal fat yield was observed for the diet having 0.30% dietary Na + . The results of the present study suggest the dietary requirements of 0.20 to 0.25% Na + and 0.30% Cl − during the finisher phase (29 to 42 d) of broiler chicks when the ambient temperature ranged from 32 to 40°C.