Dairy Cow Heat Stress Within Building Microclimates

建筑微气候中的奶牛热应激

• 批准号: BB/X009564/1
• 负责人: Christopher Reynolds
• 金额: $ 106.05万
• 依托单位: University of Reading
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FX009564%2F1
• 关键词: Dairy; Cow; Heat; Stress; Within

Lactating dairy cows generate a significant amount of body heat due to their high metabolic rates. Excess heat must be dissipated and a failure to do so leads to heat stress. The ideal ambient temperature for dairy cows ranges between 5 - 25 degree C, but this is affected by breed, feeding level, production, and other individual factors; temperatures as low as 20 degree C may lead to heat stress in some cows. Such conditions are common in the UK during summer, and can even occur in the winter, particularly indoors. Heat stress is already a problem on many UK farms, but predicted increases in average temperature and the frequency and duration of heat waves resulting from climate change, makes the issue even more urgent. Heat stress can result in a range of physiological problems including reduced feed intake and milk yield, and impaired fertility and immune function, all of which negatively affect cow welfare and the economic sustainability of dairy farms. Cows are known to adapt their behaviour to help cope with high temperatures and humidity: they may increase their intake of cold water, seek shade or areas of increased ventilation, or exhibit other individual and social behavioural responses. Not all cows show obvious physical signs of heat stress and hence monitoring has typically been based on proxy measures such as local weather station temperature and humidity records, or measurements from a few indoor sensors. However, recent research, including by our team, has shown that temperature, humidity, and ventilation within barns have high spatiotemporal variation, and are affected by both building design and usage, as well as external conditions. The presence of these barn 'microclimates' means that cows experience different individual-specific conditions, varying over time and space, that will influence their ability to cope with heat stress (and hence their subsequent physiological and behavioural responses). Social interactions and herd-level responses may also be affected by, and directly affect, the indoor microclimate: we have evidence that cows housed indoors spatially cluster with increasing temperature, a potentially maladaptive response since social clustering further increases localised temperatures.In this project we will use location tracking technology to record, in unprecedented levels of detail, patterns of movement, activity, and space-use of full herds of dairy cows under varying thermal conditions and indoor microclimates. Data will be collected for 12 months on the main study farm (CEDAR, Reading) and for shorter periods in summer and winter at 6 case-study farms with different building design and usage. Continuous sensor monitoring of barn microclimates (temperature, humidity, air quality) and detailed ventilation surveys will be combined with physiological measures (body temperature, production, health) to enable detailed analysis of how indoor-housed dairy cows respond to, and cope with, heat stress over different timescales.We will use building engineering modelling approaches to determine indoor microclimates in different farm building environments and management systems, and how these microclimates affect, and are affected by, cow behaviour. We will work directly with farmer study groups in a participatory approach to evaluate a range of potential mitigation strategies to reduce heat stress impacts under current and future climate scenarios. Working with our industry Steering Group, we will provide practical evidence-based solutions to the UK dairy industry for preventing and managing heat stress.

哺乳奶牛由于其高代谢率而产生大量的身体热量。必须散发过多的热量，并且无法这样做会导致热应力。奶牛的理想环境温度在5-25摄氏度之间，但这受到品种，进食水平，生产和其他个体因素的影响。低至20度C的温度可能导致某些母牛的热应激。这种情况在夏季在英国很常见，甚至可能在冬季发生，尤其是在室内。热应激已经成为许多英国农场的问题，但是预测平均温度的升高以及由于气候变化而导致的热浪的频率和持续时间，使问题更加紧迫。热应激会导致一系列生理问题，包括减少饲料摄入量和牛奶产量，以及生育能力和免疫功能受损，所有这些都对牛福利产生了负面影响以及奶牛场的经济可持续性。众所周知，牛会适应其行为以帮助应对高温和湿度：它们可能会增加对冷水的摄入量，寻求阴影或增加通风的区域，或者表现出其他个人和社会行为反应。并非所有的母牛都表现出明显的热应力物理迹象，因此监测通常是基于诸如当地气象站温度和湿度记录的代理措施，或者来自少数室内传感器的测量值。但是，最近的研究，包括我们的团队，表明谷仓内的温度，湿度和通风具有很高的时空变化，并且受建筑物设计和使用以及外部条件的影响。这些谷仓的“微气候”的存在意味着牛会经历不同的特定特定条件，随着时间和空间的变化，这将影响他们应对热应激的能力（因此，他们随后的生理和行为反应）。社交互动和牛群水平的反应也可能受到室内小气候的影响，并直接影响室内小气候：我们有证据表明，奶牛在室内居住的室内室内居住，随着温度的升高，社交聚类进一步提高本地性温度，这是一种潜在的适应性反应。牛在不同的热条件下和室内微气候。数据将在主要研究农场（Cedar，阅读）上收集12个月，并在夏季和冬季在6个案例研究的农场中较短的时间，具有不同的建筑设计和使用。谷仓微气候（温度，湿度，空气质量）和详细的通风调查的连续传感器监控将与生理措施（体温，生产，生产，健康）结合使用，以详细分析室内乳头奶牛对室内奶牛的响应，并在不同的时间内使用构建工具的构建机构，并确定构建工具的高度压力。微气候影响牛行为，并受到牛行为的影响。我们将直接与农民研究小组合作采用参与式方法，以评估一系列潜在的缓解策略，以减少当前和未来气候情况下的热应激影响。与我们的行业转向集团合作，我们将为英国奶牛行业提供实用的基于证据的解决方案，以防止和管理热应激。

项目成果

Bunching behaviour in housed dairy cows at higher ambient temperatures.

饲养奶牛在较高环境温度下的聚集行为。

• DOI: 10.3168/jds.2023-23931
• 发表时间: 2023
• 期刊: Journal of dairy science
• 影响因子: 3.5
• 作者: Chopra K