Assessing the welfare of growing dairy calves

这一建议的目的是回答以下广泛的问题：1.个体小牛在运动游戏和社会游戏发生方面的差异是否反映了由于疾病、低能量摄入量和/或生长不良而导致的福利差异？2.我们如何才能最好地衡量运动和社会游戏行为来评估奶牛小牛的福利？3.小牛犊达到行为发展的特定阶段的年龄(例如，社会游戏取代运动游戏、首次发情行为、吃固体饲料的能力)是否可以用来评估成长中的动物的福利？公众对农场动物福利的关注导致了农场动物的福利标准，行为的自动化监测有可能使行为衡量标准能够用于动物福利评估。奶牛犊牛福利差对成年奶牛的生产寿命有长期的影响，因此有好的方法评估奶牛的福利是很重要的。福利评估中使用的大多数指标都确定了较差的福利，但人们对使用良好福利指标的兴趣有所增加。在成长中的动物中，玩耍行为被认为是一个积极的福利指标的良好候选者。小牛表现出各种各样的运动和社交游戏，但我们需要更好的证据来证明游戏和动物福利之间的联系。大多数评估成长中动物福利的方案都是基于它们在特定年龄的状态。然而，生长中的动物的福利可能会根据它们的发育情况得到更好的评估。这项拟议的研究涉及对由自动喂养系统喂养的集体饲养的奶牛进行的一系列实验，以验证社交和运动游戏作为潜在的基于行为的指标的使用，以衡量奶牛犊的良好福利。各种游戏行为发生的时间、吃固体饲料的能力和第一次发情的时间之间的联系将表明，行为发展的一般时间是相互关联的，并受到喂养和断奶策略的影响。与后期生殖发育年龄的联系可能有助于我们理解牛的繁殖延迟问题。

The objectives of this proposal are to answer the following broad questions:1. Do variations between individual calves in the occurrence of locomotor play and social play reflect variations in welfare due to illness, low energy intakes and/or poor growth? 2. How can we best measure locomotor and social play behaviour to assess the welfare of dairy calves? 3. Can the age at which calves reach certain stages in behavioural development (e.g. replacement of locomotor play by social play, first estrous behaviours, ability to eat solid feeds) be used to assess the welfare of growing animals? Public concern about farm animal welfare has led to welfare standards for farm animals and automated monitoring of behaviour has potential to enable behavioural measures to be used in animal welfare assessments. Poor dairy calf welfare has long term impacts on the productive life of adult cow, so it is important to have good methods to assess their welfare. Most measures used in welfare assessment identify poor welfare, but there is increased interest in using measures of good welfare. Among growing animals, play behaviour has been proposed as a good candidate for a positive welfare indicator. Dairy calves show a variety of locomotor and social play but we need better evidence of the link between play and animal welfare. Most schemes for assessing the welfare of growing animals are based on their state at a particular age. However, it is likely that the welfare of growing animals may be better assessed in terms of how they are developing. This proposed research involves a series of experiments on group housed dairy calves fed by automated feeding systems, to validate the use of measures of social and locomotor play as potential behavioural-based indicators of the good welfare of dairy calves. The link between the timing of the occurrence of various play behaviours, of the ability to eat solid feed and of first estrous will show the extent that the general timing of behavioural development is inter-related and affected by feeding and weaning strategies. The link with the age of later reproductive development may help us understand the problem of delayed reproduction of cattle.