Data dependent systems analysis of stochastic swine energetic responses

1. 1.|Time series analyses implemented as data dependent systems (DDS) modelling and analyses were conducted on the stochastic energetic responses of ad libitum fed growing pigs exposed to warm constant and cyclic air temperatures. 2. 2.|The heat production responses had an exponentially decaying memory of their past events for pigs under constant air temperatures of 33 and 30.8°C, and cyclic air temperatures of 33 ± 7°C and 26 to 33°C. However, a damped memory pattern was observed for the heat production response of pigs under cyclic air temperature of 23.4 to 40°C. 3. 3.|DDS analyses on the feed intake responses showed that pigs under the 23.4-40°C treatment had a less active memory of their feeding history compared to the 30.8°C or 33°C treatment. This occurrence was possibly due to a disruption of normal feeding rhythms of the pigs by the larger temperature cycle of the 23.4 to 40°C treatment. The disrupted feeding rhythms of these pigs were also associated by reduced daily feed intake and growth rate (P < 0.01). 4. 4.|Hence, the dynamic natures of the stochastic responses as revealed by DDS analyses may be used to facilitate the identification of the thermoregulatory patterns of pigs as influenced by environmental conditions.