Abstract

Simple Summary This study examined how different types of human-animal interactions affect the welfare of nursery pigs, focusing on both their behavior and cardiac activity. Thirty-six pigs were divided into three groups based on whether they experienced positive, minimal, or rough human handling over a six-week period. Each pig was then individually tested in an experimental setting with the handler. Pigs exposed to negative handling presented more fear-related behaviors, spent less time in contact, and received fewer strokes than those handled positively. They also exhibited physiological responses indicating greater stress. Conversely, pigs handled gently displayed more affiliative behaviors and greater parasympathetic activation, potentially indicating a positive emotional state. Minimally handled pigs presented some behavioral similarities to gently handled pigs, but physiological data indicated a more positive interaction for gently handled pigs. These results emphasize how the quality of human-animal relationships impacts pigs' affective state and welfare.Abstract The human-animal relationship is crucial for animal welfare. Gentle handling enhances pigs' comfort while rough handling causes fear and stress. This study examined how different human-animal relationship qualities affect the behavior and heart rate variability (linear and non-linear parameters) of 36 nursery pigs. Over six weeks, pigs experienced positive (n = 12), minimal (n = 12), or negative (n = 12) human handling. Their responses to handlers were then assessed in an experimental arena with four phases: habituation, exposure to the handler standing and sitting, and forced interaction. Pigs subjected to negative handling exhibited increased fear-related behaviors, spending less time in contact with the handler. They also exhibited heightened stress responses, with greater LF/HF ratio and Lmean values compared with positively handled pigs. Conversely, gently handled pigs displayed affiliative behaviors, accepting more strokes, and higher parasympathetic activation, indicated by greater RMSSD/SDNN and SampEn values, suggesting a more positive affective state. Minimally handled pigs exhibited some behavioral similarities to gently handled pigs, although physiological data indicated that the interaction was likely more rewarding for the gently handled pigs. These results emphasize the impact of human-animal relationships on pig welfare and highlight the value of incorporating non-linear heart rate variability parameters in such evaluations.