ORDER IDENTIFICATION OF THE DYNAMIC HEAT PRODUCTION RESPONSE OF BROILER CHICKENS TO STEP CHANGES IN TEMPERATURE AND LIGHT INTENSITY

Abstract

In this research, the aim was to identify the order of the dynamic response of heat production of broiler chickensto steps in air temperature and light intensity. A total of 60 step experiments were performed with air temperature, and 181 stepexperiments were performed with light intensity. Each step experiment was modeled using a transfer function model. For eachexperiment, the order of the dynamic heat production response was determined using the Young identification criterion (YIC).Dynamic response of heat production to steps in temperature showed a firstorder response in 43 of the 60 experiments(i.e., 72%) and a higherorder response in the other cases (28%). Dynamic response of heat production to steps in lightintensity showed a firstorder response in 130 of the 181 cases (72%) and a higherorder response in the remaining 51 steps(28%). Based on modeling accuracy in terms of R2, applying the higherorder models improved the accuracy only in aminority (2% to 5%) of the cases. As a conclusion, it can be stated that, in general, the dynamic response of heat productionof broiler chickens to step changes in air temperature and light intensity can be modeled assuming firstorder dynamics.