Modelling the static and dynamic responses of total heat production of broiler chickens to step changes in air temperature and light intensity.

1. The objective of this work was to explore the possibilities of modelling the static and dynamic responses of total heat production of broiler chickens to step changes in temperature and light intensity (light-dark alterations) using compact dynamic model structures. 2. Seventy-seven experiments were performed in an open-circuit respiration chamber to measure the dynamic response of heat production to step variations in temperature and light (on/off). The animal responses were modelled using transfer function model structures. 3. It was demonstrated that the complex process of the dynamic response of heat production of broiler chickens to step changes in air temperature and light-dark alterations can be modelled assuming 1st order dynamics. The coefficient of determination between measured and simulated heat production was on average 0.83 for responses to air temperature and 0.93 for responses to light-dark alterations.