Sodium requirement for broilers in the growing (from 22 to 42 days) and finishing (from 43 to 53 days) phases

Seven hundred and twenty and six hundred chicks, males and females, from 22 to 42 and from 43 to 53 days old, respectively, fed a basal diet (3100 and 3210 kcal ME/kg and 19.6 and 18.6% CP) deficient in sodium (0.017%), supplemented with NaCl, corresponding to the levels of .077, .137, .197, .257 and .317% of total sodium were used to determine the sodium requirements for broilers during the growing and final phases. A completely randomized design, in a 5x2 (levels x sex) factorial arrangement, with four replicates of 18 and 15 chicks, respectively, per experimental unit, was used. Weight gain (WG), feed intake (FI), feed:gain ratio (F/G), adrenal absolute (AAW) and relative (ARW) weights, carcass yield (CY) and dry matter in the carcass (DM) and litter moisture (from 1 to 53 days old) were evaluated at the end of each phase, and the requirements were estimated by means of the polynomial regression model. WG, F/G and litter moisture were influenced by the sodium levels in both sexes, and there was no significant effect on the other parameters. Based on the performance characteristics, the sodium requirements recommended for the growing phase, estimated by the polynomial regression model, considering the biological interpretation, were of .197% for the males and at least of .317% for the females, and for the final phase were of .216 e .245%, respectively.