Mapping Thermal Environment Inside Broiler Barns for the Diagnosis of Cold Stress at Bird InitialGrowing Stage

摘要

Average temperature for the whole air volume within a broiler house may not be representative and in some cases it could mask thermal discomfort situations for broilers, especially in their growing period. At this stage, chicks are susceptible to coldstress, which might lead to developmental disorders that will compromise their overall performance. This study was conducted with the aim of mapping the dry-bulb temperature within the bird influence zone for a negative pressure barn (NPB) and a naturally ventilated barn (NVB), both for broilers, during the first three weeks of age, the investigated barns have an architecture that is usually adopted in warm climate conditions, such as Brazil, i.e. non-insulated and occasionally open by lowering the curtains. The mapping results suggested that the insulation capacity of the NVB was poorer as compared to the NPB, while average temperature during the night period was below thermoneutrality for both barns during most of the time, suggesting that both heating systems were undersized. Temperature maps also suggested that heated air was poorly mixed in the NVB during the first two weeks of age being that during the night period the cold air temperature (also in both cases) exposed the chicks to cold stresssituations.