VERTICAL TEMPERATURE PROFILES AT BIRD LEVEL IN BROILER HOUSES

1. The temperature in the close vicinity of commercial broilers was st udied in relation to the setpoint temperature throughout the rearing p eriod. 2. Mean temperature in the immediate environment of the chicks was 2.0 degrees C lower than the setpoint of 1 d of age. During the fi rst week this initial temperature difference gradually rose to 1.7 deg rees C above setpoint. At 18 d of age a further rise to a mean differe nce of 4.0 degrees C above setpoint was measured. The difference then remained constant from 32 d of age until the end of the fattening peri od. 3. It was concluded that the chickens were actually brooded at 30 degrees C. During the rearing period the ambient temperature in the cl ose vicinity of the broilers gradually declined to 26 degrees C. 4. Du ring the finishing period, ambient temperature around the broilers was far above the value recommended for optimal food intake and growth. 5 . These results are discussed in relation to heat generation and heat fluxes in the broiler houses.