Inside environment in broiler housing with new and built-up litter.

The growth of the Brazilian poultry processing facilities required to improve the productivity of the system. The thermoneutral zone is related to an ideal thermal environment, where birds have good conditions to express their productive characteristics. This work was carried out to analyze the internal microclimate in broiler houses using new bed (House 1) or reused litter (House 2), in order to understand the inference of the same on the thermal dynamics of the environment and quantify the impact of reuse from inside the house. The evaluation was based on environmental variables: air temperature, bed temperature and black globe temperature, relative humidity, air velocity and light intensity. With the collected data were calculated the rates of temperature and humidity (RTH), the rate of black globe temperature and humidity (RBGTH) and radiant heat load (RHL) of each house. In both houses the air temperature was above the recommended (27.4 and 28.0 °C). The house with reused litter had the lowest relative humidity (57.8%) and the lowest air velocity (0.7 m s-1). Comfort levels differ between systems, and thermal conditions more stressful for the birds found in the house with reused litter (RTH = 25.31 and WBGT = 25.67).