In pig breeding, environmental challenges can affect the welfare and productivity of animals. Resilient animals have the capacity to be minimally affected by these environmental challenges. Understanding the genetic basis of sensitivity to these environmental challenges is crucial for selecting more resilient animals, thereby enhancing welfare and productivity. The aims of this study were to: (1) estimate the probability of the occurrence of an unrecorded environmental challenge at a given day using daily feed intake (DFI) data, and (2) evaluate the genetic determinism of environmental sensitivity in three pig lines bred in real selection conditions. Data comprised of 100,799, 186,247, and 304,826 DFI records from 1,618, 2,517, and 3,788 Landrace (LA), Large White (LW) and Piétrain (PI) male pigs, respectively. The pedigree included 3,730, 5,649, and 9,293 animals for LA, LW, and PI, respectively. The probabilities of the occurrence of an unrecorded environmental challenge at a given day were estimated via a mixture model. The probabilities (p) of being “high CV days” were then taken as reference and used in genetic analysis as an environmental descriptor to describe the environment. DFI records were analysed using two linear models: a linear reaction norm animal model (RNAM) and the animal model. (Co)variance components were estimated using average-information restricted maximum likelihood (AI-REML). The means of the probabilities of the occurrence of an environmental challenge for LA, LW, and PI were 0.24, 0.10, and 0.22, respectively, indicating that the probability of an environmental challenge was low for most of the days. The genetic correlations between the intercept and the slope obtained from the RNAM for LA, LW, PI were -0.52, 0.06, and -0.36, respectively. These findings suggest that selecting hypothetically for decreased DFI in non-stressful conditions would result in pigs with increased DFI in stressful conditions in the LA and PI lines, whereas it would have a minor impact on the environmental sensitivity of LW. The proportion of resilient animals for LA, LW, and PI was 75.0, 74.2, and 72.2%, respectively, implying that most of the animals were resilient. The study demonstrated that the slope of DFI is heritable and can effectively be used as an indicator of sensitivity to environmental challenges. These results are valuable in improving the resilience of livestock species to environmental challenges through genetic selection.

中文翻译：

---

使用三种猪的每日采食量记录对环境挑战敏感性的遗传决定论


在养猪业中，环境挑战会影响动物的福利和生产力。适应力强的动物有能力将受这些环境挑战的影响降至最低。了解对这些环境挑战敏感的遗传基础对于选择更具适应力的动物至关重要，从而提高福利和生产力。本研究的目的是：（1） 使用每日采食量 （DFI） 数据估计在给定日期发生未记录的环境挑战的概率，以及 （2） 评估在真实选择条件下培育的三个猪系中环境敏感性的遗传决定论。数据包括分别来自 1,618、2,517 和 3,788 头长白 （LA）、大白猪 （LW） 和 Piétrain （PI） 的 100,799、186,247 和 304,826 条 DFI 记录。该系谱包括 LA、LW 和 PI 的 3,730、5,649 和 9,293 只动物。通过混合模型估计在给定日期发生未记录的环境挑战的概率。然后将“高 CV 天数”的概率 （p） 作为参考，并在遗传分析中用作描述环境的环境描述符。使用两个线性模型分析 DFI 记录：线性反应规范动物模型 （RNAM） 和动物模型。使用平均信息限制最大似然 （AI-REML） 估计 （协）方差分量。LA 、 LW 和 PI 发生环境挑战的概率均值分别为 0.24 、 0.10 和 0.22，表明环境挑战的概率在大多数日子里都很低。从 RNAM 获得的 LA、LW 、 PI 截距和斜率之间的遗传相关性分别为 -0.52 、 0.06 和 -0.36。 这些发现表明，在非应激条件下假设选择降低的 DFI 会导致 LA 和 PI 品系的猪在应激条件下 DFI 增加，而对 LW 的环境敏感性影响很小。LA 、 LW 和 PI 的适应力动物比例分别为 75.0 、 74.2 和 72.2%，这意味着大多数动物具有适应力。研究表明，DFI 的斜率是可遗传的，可以有效地用作对环境挑战敏感性的指标。这些结果对于通过遗传选择提高牲畜物种对环境挑战的适应能力很有价值。