Use of thermal imaging for the early detection of signs of disease in pigs challenged orally with Salmonella typhimurium and Escherichia coli

A total of 27 piglets were randomly assigned to three treatment groups (control, infection with Salmonella enterica serover Typhimurium KCTC 2515 (ST) and infection with Escherichia coli KCTC 2571 (EC)) in a completely randomized design to early detection of signs of disease based on body temperature. Totally three inoculations were done consisting of 14 days each and then thermal images were captured to calculate body temperature of pigs at 0, 2, 6, 12, and 24 h and then every 24 h up to 14 days post inoculation. A reduced average daily gain (ADG) was observed in the first week of all three post inoculation (P < 0.05), while the gain:feed ratio was decreased at first week during first inoculation in both ST and EC group compared to control (P < 0.05). Body temperature was elevated in ST infected piglets at 24 h, peaked at 72 h (P < 0.05) and remained elevated, however, the EC induced piglets showed a subnormal body temperature throughout the experimental period relative to the control (P < 0.05). Taken together, the results indicate that signs of disease following experimentally induced bacterial infection in pigs can be detected quickly and easily using thermal images.