Effect of feed intake level on the body temperature of pigs exposed to heat stress conditions

Feed intake (FI) level affects body heat production in thermo-neutral pigs; exposure of pigs to heat stress (HS) also increases body temperature (BT). However remains unclear whether the FI level affects the heat production of HS pigs. This study analyzed the effect of FI level on BT of 9 HS pigs (46.3 ± 2.6 kg body weight) implanted with a thermometer set to register the BT at 5-min intervals into the ileum. Pigs were divided in two groups randomly allotted to two FI treatments: high FI (HFI, 1.20 kg/d), and low FI (LFI, 0.96 kg/d), according to a two-period crossover experimental design. Pigs were fed 3-times a day (0600, 1200, and 2200 h), same amount each time (400 g or 320 g). Ambient temperature (AT) ranged from 29.0 to 35.4 °C. The BT of both HFI and LFI pigs followed a similar pattern along a 24-h period, but the BT of HFI pigs was higher than that of LFI pigs (P