Eight hundred Avian Farms chicks (50% males; 50% females) from 1 to 21 days of age, averaging 40.5 g, fed a basal diet (3.000 kcal ME/kg and 21.1% CP) deficient in sodium (0.017%) and supplemented with NaCl, corresponding to the levels of 0.077, 0.137, 0.197, 0.257 and 0.317% total sodium, were used to determine the sodium requirement. A completely randomized design, in a 5x2 (sodium levels x sex) factorial design, with four replicates and 20 chicks per experimental unit, were used. Weight gain, feed intake, feed:gain ratio, adrenal absolute weight and relative weight, carcass yield and carcass dry matter were evaluated, and the requirements were estimated by means of the polynomial regression models. The sodium supplementary levels affected weight gain, feed intake, feed:gain ratio and adrenal relative weight in both sexes, with no significant effect of the studied levels on the adrenal absolute weight, carcass yield and carcass dry matter. It was demonstrated that the biometric evaluations (adrenal weight) are not good parameters to determine the requirement, because of the high coefficient of variation values obtained in the study. Based on the birds performance, the minimum recommended sodium requirements, estimated by the polynomial model, were of 0.256 and 0.255%, for males and females, respectively.
adrenal gland; broiler chicks; carcass; nutritional requirements; salt; sodium
