a These authors contributed equally to this work. AbstractThe aim of this study was to quantify the body surface temperature of suckling piglets, and determine the association between body surface temperature, body weight and growth rate during the suckling period. The study population consisted of 72 piglets from six sows that were randomly selected at day 4 after farrowing. Infrared thermography and weighing were performed every other day from day 4 to 24 of lactation. Thermal images of each piglet were taken at the eye, base of ear, back, and anus using a handheld infrared camera. Body surface temperature was associated with piglet age and growth rate (P < 0.05), but not with body weight. At day 14, the body surface temperature was highest in all regions (P < 0.05), while at day 24 the piglets averaged lower body surface temperatures than at days 4-18 (P < 0.05). The interaction between piglet age and growth rate significantly affected body surface temperature (P < 0.05). The body surface temperature only varied with growth rate in piglets 12 and 14 days old after birth (P < 0.05). In conclusion, infrared thermography might be useful for the detection of body surface temperature that can be used as an indication of growth performance in piglets with health problems.