An experiment was conducted to investigate the effects of different cooling systems on bird thermal comfort, litter moisture content and the performance of broiler breeders, housed in open facilities at high temperatures conditions in Brazil. The study used Hubber lineage birds, from 26 to 37 weeks of age, in summer and fall conditions, in the Minas Gerais State, Brazil. Two facilities were used, with similar dimensions and construction characteristics, oriented in an east-west direction. Six replicates of six different systems of environmental control were evaluated: (fan jet with polytube and evaporative cellulose pad material, FJS; roof sprinkling (exterior), RSS; internal fogging system, IFS; two horizontal mixing fans directing air into the room, MFS; two roof-top wind-driven turbine ventilators, RVS; and a conventional system as the control, CTL, with ventilation provided solely by wind and no additional cooling. Hatchability, AH, was measured weekly. Results demonstrated that the FJS, IFS and MFS systems, in this sequence, performed best, presenting reduced BGHTI values and improved AH as compared to the other systems. Results obtained from the RVS and the CTL systems were markedly inferior. Litter moisture content (MC) was least in the MFS system while greatest in the FJS system.