ABSTRACT

This study assessed acute pain in piglets during castration through behavioral indicators. Piglets (n=88) were randomly allocated to one of two treatments: surgical castration and sham-castration. Within 24 hours after birth, identical castration procedures were followed for both treatment groups, except sham piglets were not castrated. Struggle behavior (curl ups, leg kicks, and body flailing) and vocalization (duration and peak frequency) were analyzed during the castration procedure. Castrated piglets kicked more frequently than sham piglets (28.8 vs. 21.3 kicks/min, SE = 0.09; P = 0.02). Additionally, 51.2% of castrated piglets displayed body flailing, whereas only 4.4% of sham piglets displayed the same behavior (P = 0.03). Castrated piglets responded with more high frequency (≥1,000 Hz) calls than sham piglets (23.6 vs. 18.6 calls/min, SE = 0.26; P = 0.04) and high frequency calls tended to be of longer duration for castrated piglets (0.45 vs. 0.27 sec/call, SE = 0.04; P = 0.08). Results indicate that surgical castration increased the frequency of leg kicks, body flailing, and high frequency calls compared to sham-castration, suggesting these may be useful behavioral indicators of acute pain in piglets.

摘要

本研究通过行为指标评估去势期间仔猪的急性疼痛。仔猪（n=88）被随机分配到两种治疗中的一种：手术去势和假去势。出生后 24 小时内，两个治疗组均遵循相同的去势程序，但假仔猪未进行去势。在阉割过程中分析了挣扎行为（蜷缩、踢腿和身体甩动）和发声（持续时间和峰值频率）。去势仔猪比假仔猪更频繁地踢腿（28.8 vs. 21.3 踢腿/分钟，SE = 0.09；P = 0.02）。此外，51.2% 的去势仔猪表现出身体摆动，而只有 4.4% 的假仔猪表现出相同的行为 (P = 0.03)。去势仔猪的响应频率（≥1,000 Hz）比假仔猪更高（23.6 对 18.6 次/分钟，SE = 0.26; P = 0.04），去势仔猪的高频叫声往往持续时间更长（0.45 对 0.27 秒/叫声，SE = 0.04；P = 0.08）。结果表明，与假去势相比，手术去势增加了踢腿、身体甩动和高频呼叫的频率，这表明这些可能是仔猪急性疼痛的有用行为指标。