Quantification of the order dynamics of heat production response of broiler chickens to steps in temperature and light intensity

摘要

In this research the aim was to investigate the order of the dynamic response of heat production of broiler chickens to steps in air temperature and light intensity. In total 60 step experiments were performed with air temperature and 181 step experiments with light intensity. Each step experiment was modelled using a transfer function model. For each experiment the order of the dynamic heat production response was determined using YIC (Young's Information Criterion). Dynamic response of heat production to steps in temperature showed a first order response in 43 of a total of 60 experiments (i.e. 72 percent). In the other cases (28 percent), YIC indicated a higher order response. Dynamic response of heat production to steps in light intensity showed a first order response in 130 of the 181 cases (72 percent) and a higher order response in 51 of the 181 steps (28 percent). Looking at the modelling accuracy in terms of R_T~2, applying the higher order models improved the accuracy only in a minority(2 to 5 percent) of the cases. As a conclusion, it can be stated that in general the dynamic response of heat production of broiler chickens to steps air temperature and light intensity can be modelled assuming first order dynamics.