Ensuring humane deaths for laboratory birds

确保实验室鸟类的人道死亡

• 批准号: 2751290
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2751290
• 关键词: Ensuring; humane; deaths; laboratory; birds

Humane methods of killing for laboratory animals are expected by society and are essential for maintaining public trust in science. Robust application of the 3Rs and cost-benefit analysis underpins ethical approval of research involving animals, ensuring minimal harms are weighted against optimised benefits. Schedule 1 killing describes certain approved, assumed to be humane methods, commonly applied as part of scientific studies for tissue collection, to fulfil legal requirements on conclusion of the research work, or as a routine part of breeding of transgenic lines. Domestic fowl (chickens) are the primary bird species used for experimental procedures in the UK, with 124,078 birds bred and used in experimental procedures in 2019 (Home Office, 2019). Large numbers of chicks are killed in the first week of life after genotyping, for husbandry management, or in research targeted at the neonatal stages of development. Current permitted methods for despatching newly hatched chicks are cervical dislocation, exposure to carbon dioxide (CO2) in a rising concentration, concussion of the brain and anaesthetic overdose. While these Schedule 1 methods have been assessed in rodents, the evidence base for their use and reliability in small birds is extremely limited or absent. In fact, there is a dearth of published studies evaluating Schedule 1 killing methods in birds of less than 7 days of age in research contexts, and despite the scale of the global poultry industry, relevant research in agricultural settings is also limited. Even studies on older birds have taken place in the farm animal context, where numerous practical and food safety constraints apply - most of which are not relevant to laboratory settings. For example, there is a lack of research on the welfare implications of exposure to a rising concentration of CO2 and the issue of CO2 exposure in general is becoming increasingly controversial. Overdose of anaesthetic via intravenous injection has been associated with good welfare outcomes, but it is difficult to perform in small and/or young birds and the handling involved can cause fear and distress. Intraperitoneal injection is associated with tissue irritation and extended time to death in rodents. Exposure to inert gases and hypobaric hypoxia (via exposure to gradual decompression) have been positively assessed in adult birds within the food chain and appear promising for chicks, but these are not currently available Schedule 1 killing methods. The remaining physical methods: concussion and cervical dislocation (which is most commonly used) are associated with significant issues in terms of reliability and training standards in adult chickens and their welfare implications in newly hatched chicks are unknown. In short, there is either limited or no evidence that current Schedule 1 methods for chicks are associated with acceptable welfare outcomes.The aim of this project fills this knowledge gap by systematically evaluating the welfare implications of current and novel methods of killing of newly hatched chicks (of both broiler and layer strains), to (i) validate or reject current methods, depending on welfare outcomes; and (ii) underpin the addition of new humane methods to Schedule 1. We will integrate behavioural, physiological, neurophysiological and pathological data to assess the types and severity of suffering prior to loss of consciousness for each tested method, a robust approach that we have validated in previous work. This project will result in detailed, scientifically sound guidance for killing methods of newly hatched chicks, ensuring humane deaths. Such guidance will be tailored to strain and age, improving the welfare of newly hatched chicks in research facilities. It is also likely that the findings will have important implications for routine procedures in poultry meat and egg production, where chicks are regularly culled.

社会期望用人道的方法杀死实验动物，这对维持公众对科学的信任至关重要。3r原则和成本效益分析的有力应用支持了动物研究的伦理批准，确保最小的危害与最优的效益相权衡。附表1描述了某些经批准的、被认为是人道的方法，通常作为收集组织的科学研究的一部分，以满足研究工作结束时的法律要求，或作为转基因品种育种的常规部分。家禽（鸡）是英国用于实验程序的主要鸟类，2019年饲养了124,078只家禽并用于实验程序（Home Office, 2019）。大量雏鸡在基因分型后的第一周内被杀死，用于饲养管理，或用于针对新生儿发育阶段的研究。目前被允许的处死新孵化小鸡的方法有颈椎脱臼、暴露在浓度上升的二氧化碳中、大脑脑震荡和麻醉过量。虽然这些附表1的方法已在啮齿动物中进行了评估，但在小型鸟类中使用这些方法及其可靠性的证据基础极其有限或缺乏。事实上，在研究背景下，评估附表1规定的7日龄以下禽鸟屠宰方法的已发表研究缺乏，尽管全球家禽业规模庞大，但农业环境下的相关研究也很有限。即使是对老年鸟类的研究也是在农场动物环境中进行的，那里有许多实际和食品安全限制，其中大多数与实验室环境无关。例如，缺乏对暴露于二氧化碳浓度上升的福利影响的研究，而二氧化碳暴露问题总体上正变得越来越有争议。通过静脉注射过量麻醉剂与良好的福利结果有关，但在小型和/或雏鸟中很难执行，并且所涉及的处理可能导致恐惧和痛苦。在啮齿类动物中，腹腔注射与组织刺激和延长死亡时间有关。对食物链中的成年鸟类暴露于惰性气体和低气压缺氧（通过暴露于逐渐减压）进行了积极评估，对雏鸟来说似乎很有希望，但这些目前还不是附表1中可用的杀死方法。其余的物理方法：脑震荡和颈椎脱臼（最常用的）在成年鸡的可靠性和训练标准方面存在重大问题，它们对新孵化的小鸡的福利影响尚不清楚。简而言之，目前的附表1雏鸡饲养方法与可接受的福利结果相关的证据要么有限，要么没有。该项目的目的是通过系统地评估当前和新的屠宰新孵化雏鸡（肉鸡和蛋鸡品种）的方法对福利的影响来填补这一知识空白，以(i)根据福利结果验证或拒绝当前的方法；（ii）支持在附表1中增加新的人道方法。我们将整合行为、生理、神经生理和病理数据，以评估每种测试方法在失去意识之前的痛苦类型和严重程度，这是我们在之前的工作中验证过的一种可靠方法。该项目将为新孵化小鸡的屠宰方法提供详细、科学合理的指导，确保人道死亡。这种指导将根据品种和年龄进行调整，以改善研究设施中新孵化的小鸡的福利。这些发现也可能对家禽肉类和蛋类生产的常规程序产生重要影响，在这些程序中，小鸡被定期剔除。