PSVII-27 Nasal surface temperature variation before, during and after routine interventions

Abstract Routine practices such as teeth clipping (TEE), tail docking (TAI) and ear tagging (TAG) can be considered controversial due to the potential pain or stress they might cause. This study sought to evaluate how nasal surface temperature changes before, during and after each of these procedures (TEE, TAI, TAG) as performed routinely on a commercial farm. A total of 116 crossbred piglets (Landrace x Large white x Duroc Danish) from multiparous sows were used. As litters were processed, thermographic images were taken using a high-resolution handheld infrared camera FLIR T650sc (640 x 480 pixels; FLIR Systems, Wilsonville, OR) at a uniform distance of 1 m on the left side of the face. All thermal images were collected between 0900 and 1600 h. To assess procedures separately, a recovery period (12 ± 2.5 min) was allowed between procedures. Due to order differences in which procedures were implemented, the following study groups were created (procedures in brackets indicate the procedures performed prior to the procedure being assessed): TEE, (TEE+) TAI, (TEE+TAI+) TAG, TAI, (TAI+) TEE, (TAI+TEE+) TAG, TAG, (TAG+) TEE, (TAG+TEE+) TAI. Temperature values were recorded from images using FLIR Tools software 6.0 (FLIR Systems). GraphPad Prism 10.0.2 (San Diego, CA) statistical software was used to analyze the obtained data. All data were analyzed via a linear mixed model for repeated measures and Multiple comparisons were calculated using a post-hoc Tukey test (GraphPad Prism 10.0.2). There were no significant differences in Nasal surface temperature among groups at any time points (Table 1, P > 0.05). However, there was a significant reduction in temperature from before the procedure(s) to during and after the procedures in the TAG (P = 0.006) and the (TEE+) TAG (P < 0.001) groups. Changes in the surface temperature of piglets can be related to the sympathetic activity and the hypothalamic-pituitary-adrenal axis activation during the perception of a stressor, which causes a sympathetically mediated acute vasomotor response that shifts cutaneous capillary blood flow due to transient peripheral vasoconstriction. Infrared thermography recognizes such blood flow changes as a reduction in the amount of heat radiated from the skin. Indeed, the nasal surface temperature was reduced in TAG and (TEE+) TAG piglets during and after the procedure(s) which suggests these procedure groups caused a greater degree of thermal change to the piglets. Furthermore, the results suggest that infrared thermography could be a useful tool to assess the impact of routine husbandry practices on piglet welfare. Nonetheless, further research should assess infrared thermography alongside behavioral and physiological assessments to establish the relationship between surface temperature and stress during husbandry procedures.