Differences in how individuals cope with stressful conditions (e.g. novel/unfamiliar environment, social isolation and increases in human contact) can explain the variability in data collection from nutrient digestibility trials. We used the collared peccary (Pecari tajacu), which is under process of domestication and shows high individual behavioral distinctiveness in reactions toward humans, to test the hypothesis that behavioral differences play a role in nutrient digestibility. We assessed the individual behavioral traits of 24 adult male collared peccaries using both the ‘behavioral coding’ and the ‘subjective ratings’ approaches. For the behavioral coding assessment, we recorded the hourly frequency of behaviors potentially indicative of stress during the 30-day habituation period to the experimental housing conditions. The subjective ratings were performed based on the individuals’ reactions to three short-term challenge tests (novel environment, novel object and threat from a capture net) over a period of 56 days. During the last 26 days, the collared peccaries were fed diets either high (n = 12) or low (n = 12) in dietary fiber levels, and we determined the total tract apparent digestibility of nutrients. The individual subjective ratings showed consistency in the correlated measures of ‘relaxedness’, ‘quietness’ and ‘satisfaction’ across the three challenge tests, which were combined to produce z score ratings of one derived variable (‘calmness’). Individual frequency of BPIS/h and calmness scores were negatively correlated and both predicted the total tract digestibility of acid detergent fiber (ADF), which ranged from 0.41 to 0.79. The greater the calmness z scores (i.e. calmer individuals), the greater the total tract digestibility of ADF. In contrast, the higher the frequency of BPIS/h, the lower the total tract digestibility of ADF. Therefore, our results provide evidence that by selecting calmer collared peccaries, there will be an increase in their capacity to digest dietary fiber.

个体应对压力条件（例如，新的/陌生的环境，社会隔离和人与人之间的接触增加）的方式差异可以解释营养物消化率试验数据收集的可变性。我们用领野猪（Pecari tajacu），这是在驯化过程中，在对人类的反应中显示出很高的个人行为特征，以检验行为差异在营养物质消化率中起作用的假说。我们使用“行为编码”和“主观评分”方法评估了24名成年雄性领领兽的个体行为特征。对于行为编码评估，我们记录了可能在30天的习惯性居住期间对实验性住房条件产生压力的行为的每小时频率。主观评分是根据个人在56天内对三种短期挑战测试（新颖环境，新颖物体和来自捕获网的威胁）的反应进行的。在过去的26天里，给领领猫科动物喂了高剂量的饮食（n = 12）或低（n = 12）的膳食纤维水平，我们确定了养分的总表观消化率。在三个挑战测试中，个人主观评分在“放松”，“安静”和“满意度”的相关度量中显示出一致性，这些度量结合起来得出一个派生变量的z评分（“平静”）。个体的BPIS / h频率与镇静度得分呈负相关，并且均预测酸性洗涤剂纤维（ADF）的总束消化率介于0.41至0.79之间。平静度z越大得分（即较平静的人）时，ADF的总道消化率越高。相反，BPIS / h的频率越高，ADF的总消化率越低。因此，我们的结果提供了证据，表明通过选择镇定领领的胸果，它们消化膳食纤维的能力将会提高。