Comparing The Thermal Environmental In Broiler Housing Using Two Bird's Densities Under Tropical Conditions

Brazilian farmers have adopted high bird density associated to auxiliary management such as adapted tunnel ventilation system in order to optimize broiler productions and to provide thermal comfort for the reared birds. This research compared two distinct broiler’s lodging systems in three commercial flocks and similar outside conditions using: a conventional housing system lodging 13 birds/m2 (G1) and an adapted tunnel based on a combination of positive and negative pressure with side walls closed with curtains with broilers housed at density of 18 birds/m2 (G2). Environmental variables such as dry bulb (DBT) and black globe (BGT) temperatures, relative humidity (RH) and inside air speed (AS) were recorded, while the temperature daily fluctuation (DF) and the effective temperature (ET) were calculated. The bird’s behavior was observed and the broiler’s weight gain and percentage of mortality were measured. Results showed that there was no difference in the physical environmental profile of both housings, even though they had distinct bird’s densities. The values of relative humidity (RH) in both systems were higher than the ones found outside due to the use of fogging inside. Broiler's weight gain was not statistically different in both systems, however as total number of birds was higher in G2 the final results of meat production was higher in G2 than in G1. Better distribution of air flow over the birds in the adapted tunnel ventilation system G2 apparently alleviated the broiler’s heat stress.