The objective ofthis experiment was to evaluate the effect of diet supplementation with vitaminsC and E and organic minerals Zn and Se on immunological parameters of broilersfrom 1 to 35 days, kept on cyclic heat stress (25 to 32°C) and to evaluatethe usefulness of bovine serum albumin (BSA) inoculation to determine humoralimmunity. A total of 272 Ross broilers were used to evaluate four types of vitamin-mineralsupplementation (VMS): D1- control diet with 60 and 30 IU of vit E for starterand growing diet, respectively, zero vit C, 80 ppm of inorganic Zn, 0.3 ppmof inorganic Se; D2 - control diet + 100 UI vit E and 300 ppm vit C/kg; D3 -control diet + 40 ppm Zn and 0.3 ppm Se/kg, both from organic sources; D4 -control diet and levels of VMS used in D2 and D3), and two environments: thermoneutral(TNA) and cyclic heat stress (CHS) from 14 days of age. Six and five birds pertype of supplementation in CHS and TNA, respectively, were inoculated with BSAat 12 and 24 days. Birds serum at 35 days-old was analyzed by ELISA. Supplementationwith vitamins and minerals did not influence antibody production of broilerschallenged with BSA. Heat stress improved antibody anti-BSA production regardlessof the diet. Inoculation with BSA did not influenced broiler performance andwas a good strategy to evaluate humoral immunity of broilers, since the birdsresponded to the challenge improved antibody production and increased bursalsize, despite the higher individual variation.
