Spatial variability of enthalpy and illuminance in free-range broiler sheds

ABSTRACT Free-range broiler producers are concerned with the thermal environment and lighting of their facilities and seek to improve these factors for the increased welfare of their broilers. The objective of this study was to evaluate the spatialization of illuminance and enthalpy in two free-range broiler sheds, one of masonry with a clay tile roof and the other built of wood with a straw roof. The data on air temperature, relative air humidity, and illuminance were recorded between September and October 2018 for five non-consecutive weeks in two periods during the day: morning (9 hours) and afternoon (15 hours). The data were collected at 42 points per shed, spaced 0.40 × 0.75 m. The experimental design was completely randomized in a 2 × 2 factorial scheme, considering two periods and two sheds. Spatial dependence was evaluated using geostatistics and interpolation maps by kriging. The facilities presented strong or moderate spatial dependence for all observed variables and periods. The small edges and lack of management of curtains resulted in the masonry shed having higher illuminance values during both periods. Although it did not present ideal values for a comfortable environment, the wood shed was more thermally efficient.