Thermography as a tool for the assessment of stress and affective states in an avian model

动物福利是一个重要的问题，影响健康，福祉和/或生产力的动物在广泛的背景下，如农场，实验室和野生动物。有效和可靠的福利评估技术对于查明问题和在这一领域取得进展至关重要。目前的福利评估方法可能很耗时，主要依赖于测量表明疼痛或痛苦的行为反应，如发声或更微妙的变化，如抑制正常行为、改变行为方向或改变行为模式。还采用了生理学方法来评估福利，这些方法基于通常在血液中测量的应激激素的释放。虽然这种方法已经很成熟，但它通常是侵入性的（需要血液样本），这些激素的循环水平可能会受到压力以外的许多生物因素的影响。也许最重要的是，到目前为止，基于激素的福利评估主要集中在消极状态的测量上，我们目前还没有一种测量方法可以可靠地区分积极和消极的心理或情绪状态。需要更可靠、侵入性更小或耗时更少的新技术。在应激事件中，身体的快速生理变化改变了血液流动的模式，将血液从动物的外周引导到其身体核心。这导致身体核心的变暖和皮肤的局部冷却，这些变化发生在急性（短期）压力以及慢性（长期）stress.Recent进展热成像摄像机提供了一个机会，开发远程方法评估动物的福利。热成像，也称为红外热成像，通过测量动物发出的热辐射量来记录动物的表面温度。因此，表面温度是血流量的间接测量，并且有可能成为评估对应力的生理反应的非侵入性方法，而无需血液采样或探针连接。最重要的是，有证据表明，这种方法可能能够区分动物的消极和积极的精神状态。本研究项目的目的是验证使用红外热成像作为一种新颖的，非侵入性的工具，以提供相关的和即时的信息福利状态的鸟类。我们将致力于家禽（蛋鸡），这是高度相关的物种，因为英国家禽业每年饲养数百万只家禽。商业家禽可能受到禁闭、跛足、饥饿、未确诊的疾病或处理不当的影响，我们需要更好的方法来评估它们的福利。通过比较表面温度对相同短期应激源的严重程度增加的反应，确定表面温度测量作为应激指标的准确性，并检查对不同类型应激源的反应。我们将验证这些信息对完善的福利措施，包括压力激素，核心体温和行为。2.通过检查对长期压力情况的反应并将其与无压力的鸟类进行比较，确定热成像技术作为慢性压力的指标。3.检查体表温度模式与消极和积极的精神状态相关的程度，以确定热成像是否可以成为区分好和坏福利的新方法。这项工作将使我们对鸟类对压力的热反应的理解取得重大进展。该研究所将开发适当的温度记录方法，用于福利评估，并确定这种技术在商业上应用的潜力，以监测鸟类的福利。

Animal welfare is an important issue influencing the health, wellbeing and/or productivity of animals in a wide range of contexts such as farm, laboratory and wild animals. Effective and reliable welfare assessment techniques are essential to identify issues and make progress in this area. Current approaches to welfare assessment may be time consuming and rely primarily on measuring behavioural responses that are indicative of pain or distress such as vocalisations or more subtle changes such as suppression of normal behaviour, redirection of behaviour or changes in behaviour patterns. Physiological approaches to welfare assessment have also been used and these are based on the release of stress hormones which are usually measured in the blood. While this approach is well established, it is usually invasive (requiring a blood sample) and circulating levels of these hormones may be influenced by many biological factors other than stress. Perhaps most importantly, hormone based welfare assessment has so far focused on the measurement of negative states, and we do not currently have a measurement approach that can reliably differentiate between positive and negative mental or emotional states. New techniques are required that are more reliable and less invasive or time-consuming. During stressful events, rapid physiological changes in the body alter the pattern of blood flow, directing blood away from the periphery of the animal to its body core. This leads to warming of the body core and localised cooling of the skin and these changes occur in response to both acute (short term) stress as well as chronic (longer term) stress.Recent advances in thermal imaging cameras provide an opportunity to develop remote methods of assessing the welfare of animals. Thermal imaging, otherwise known as infrared thermography, records the surface temperature of an animal by measuring the quantity of thermal radiation it emits. Surface temperature is therefore an indirect measurement of blood flow and has the potential to be a non invasive method of assessing physiological responses to stress without the need for blood sampling or probe attachment. Most importantly, there is evidence that this method may be able to distinguish between negative and positive mental states in animals.The aim of this research project is to validate the use of infrared thermography as a novel, non invasive tool to provide relevant and immediate information on welfare state in birds. We will work on the domestic fowl (laying hen) which is highly relevant species because millions of birds are reared annually in the UK poultry industry. Commercial poultry may be affected by confinement, lameness, hunger, undiagnosed disease or poor handling and we need better ways of assessing their welfare.The specific objectives of this work are to:1. Determine the accuracy of surface temperature measures as indicators of stress by comparing surface temperature in responses to increasing severities of the same short term stressor and also examine responses to different types of stressors. We will validate this information against well established welfare measures including stress hormones, core body temperature and behaviour. 2. Establish the use of thermography as an indicator of chronic stress by examining responses to long term stressful situations and comparing these to unstressed birds. 3. Examine the extent to which body surface temperature patterns are associated with negative and positive mental states, to determine if thermal imaging could be a novel way of distinguishing good and bad welfare. The work will lead to significant advances in our understanding of the thermal responses to stress in birds. It will develop appropriate thermographic approaches for welfare assessment and establish the potential for commercial application of this technique to monitor the welfare of birds.