Castration is a painful procedure routinely performed on piglets. Specific periods relative to castration and time sampling rules are used widely to quantify deviations in piglet’s behavior associated with castration rather than assessing behavior for the entire trial period. However, very limited work has evaluated time sampling recording rules to quantify behavioral changes to piglets undergoing castration. Therefore, the objective of this study was to validate the accuracy of six continuous time sampling periods (5, 10, 15, 20, 30, and 45 min), to quantify piglet behavior post-castration when compared with a full 60-min observation period. Sixteen Yorkshire-Landrace x Duroc piglets were surgically castrated. Data were collected using continuous observation (recording rule) of each individual male piglet per litter for 60-min post-castration. The 60-min continuous behavioral data set was then subdivided into six data subsets for each defined continuous time sampling period (5, 10, 15, 20, 30, and 45 min). Data from each continuous time sampling period and the full period data were analyzed using both a generalized linear mixed model and linear regression analysis. For the generalized linear mixed model, 30- and 45-min continuous time sampling periods were not different (P > 0.05) when compared with the full observation period data for all behaviors. For the linear regression analysis, affiliative interaction, sitting, walking, huddled up, prostrated, scratching, spasms, and trembling behaviors met the pairwise comparison accuracy criteria: [1) the coefficient of determination (R2) was > 0.90, 2) the intercept did not differ from 0 (P > 0.05), and 3) the slope did not differ from 1 (P > 0.05)] at the 45-min continuous time sampling period compared to full observation period. Results from this study suggest that a 45-min continuous time sampling period would be necessary to accurately investigate piglet behavior during the acute pain sensitivity time post-castration when considering both maintenance and pain-associated behaviors.

中文翻译：

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技术贡献：使用连续记录视频监控手术去势后仔猪的维持和疼痛行为，以验证行为评分的六个连续时间采样周期

阉割是一种痛苦的程序，通常对仔猪进行。与去势相关的特定时期和时间抽样规则被广泛用于量化与去势相关的仔猪行为偏差，而不是评估整个试验期间的行为。然而，非常有限的工作评估了时间采样记录规则，以量化阉割仔猪的行为变化。因此，本研究的目的是验证六个连续时间采样周期（5、10、15、20、30 和 45 分钟）的准确性，与完整的 60 分钟观察相比，量化阉割后的仔猪行为时期。对 16 头约克郡-长白 (Yorkshire-Landrace) x 杜洛克 (Duroc) 仔猪进行了手术阉割。使用每窝雄性仔猪在阉割后 60 分钟的连续观察（记录规则）收集数据。然后，针对每个定义的连续时间采样周期（5、10、15、20、30 和 45 分钟），将 60 分钟的连续行为数据集细分为六个数据子集。使用广义线性混合模型和线性回归分析对来自每个连续时间采样周期和整个周期数据的数据进行分析。对于广义线性混合模型，与所有行为的完整观察期数据相比，30 分钟和 45 分钟连续时间采样周期没有差异（P > 0.05）。对于线性回归分析，亲和互动、坐、走、蜷缩、俯伏、抓挠、痉挛和颤抖行为符合成对比较准确度标准：[1) 决定系数 (R2) 大于等于 0.90, 2) 截距与 0 没有差异 (P > 0.05), 3) 与完整观察期相比，在 45 分钟连续时间采样期间，斜率与 1 没有差异 (P > 0.05)]。这项研究的结果表明，在考虑维持和疼痛相关行为时，需要 45 分钟的连续时间采样期来准确调查去势后急性疼痛敏感性时间内的仔猪行为。