PDF(Pubmed)
Abstract：
Most studies of the effects of housing and husbandry on animals\' affective states and welfare investigate the impact of stable living conditions, comparing for example, animals living in enriched environments with those living in non-enriched ones. Changes in living conditions, including from more to less enriched environments, have also been found to have effects on measures of affective state and welfare in some species. But these studies have not investigated whether it is the trajectory of change that has affected the animals (e.g., worsening conditions), or simply the nature of their final environment (e.g., non-enriched). Here, we hypothesised that laying hens living in worsening conditions across a six-week period (gradually moving from preferred to non-preferred living conditions; \"Trajectory to Non-Preferred\", TNP, n = 30), would show evidence of more negative affective states and poorer welfare than those living continuously in non-preferred conditions for the same duration (\"Stable Non-Preferred\", SNP, n = 30). We also hypothesised that hens living in improving conditions (gradually moving from non-preferred to preferred living conditions; \"Trajectory to Preferred\", TP, n = 30), would show evidence of more positive affective states and better welfare than those living continuously in preferred conditions (\"Stable Preferred\", SP, n = 30). The preferred living condition provided extensive resources and intermittent rewarding events (such as the delivery of food treats) known to be valued and preferred by most hens, while the non-preferred living condition provided just basic resources and intermittent aversive events (e.g., loud noises). The hens\' affective states and welfare were measured using home-pen behavioural observations, body condition assessments, physiological stress measures (e.g., blood corticosterone, glucose, etc.), physical challenge tests, and judgement bias tests. A number of differences between hens in the trajectory and stable living conditions were found: TP hens were lighter, showed more foraging behaviour and less standing alert and head-shaking than SP hens, while TNP hens showed more head-shaking, mild feather pecking and aggressive attacking of pen mates than SNP hens. However, some of these differences failed to reach significance following Benjamini adjustments for multiple testing. The groups also did not differ in their judgement biases (measured in a sub-sample of 12 hens per experimental group), response to physical challenges, or measures of physiological stress. We conclude that the hens in the present study showed some evidence of responsiveness to \'affective trajectories\' in their living conditions, but no definitive effects on their affective states and welfare.
摘要：
大多数关于住房和畜牧业对动物情感状态和福利的影响的研究都调查了稳定生活条件的影响。例如，比较，生活在丰富环境中的动物和生活在非丰富环境中的动物。生活条件的变化，包括从更丰富到更不丰富的环境，还发现对某些物种的情感状态和福利措施有影响。但是这些研究并没有调查是否是变化的轨迹影响了动物(例如，条件恶化)，或者仅仅是他们最终环境的性质(例如，非丰富)。这里,我们假设产蛋鸡在六周内生活在恶化的条件下(逐渐从首选到非首选的生活条件；“对非首选的轨迹”，TNP,n=30),与那些在相同持续时间内连续生活在非首选条件下的人相比，将显示出更多的负面情感状态和更差的福利(“稳定的非首选”，SNP,n=30)。我们还假设母鸡生活在改善的条件下（逐渐从非首选到首选的生活条件；“轨迹到首选”，TP,n=30),与那些连续生活在首选条件下的人相比，将显示出更积极的情感状态和更好的福利(“稳定的首选”，SP,n=30)。首选的生活条件提供了广泛的资源和间歇性奖励事件（例如提供食物对待），这些事件被大多数母鸡所重视和喜欢，而非优先生活条件仅提供基本资源和间歇性厌恶事件(例如，噪音很大)。母鸡的情感状态和福利是使用家庭围栏行为观察来衡量的，身体状况评估，生理应激措施(例如，血皮质酮，葡萄糖，等。),物理挑战测试，和判断偏差测试。发现母鸡的轨迹和稳定的生活条件之间存在许多差异：TP母鸡较轻，比SP母鸡表现出更多的觅食行为和更少的站立警觉和摇头，而TNP母鸡表现出更多的摇头，比SNP母鸡温和的羽毛啄食和对围栏伴侣的攻击性攻击。然而,在Benjamini对多重测试进行校正后,其中一些差异未能达到显著性.各组的判断偏差也没有差异（在每个实验组12只母鸡的子样本中测量），对身体挑战的反应，或测量生理压力。我们得出的结论是，本研究中的母鸡在其生活条件下表现出对“情感轨迹”的反应性的一些证据，但对他们的情感状态和福利没有明确的影响。
