Optimizing energetic efficiency in cold adapted beef cattle

在过去的十年中，冬季对牛的管理已经从在旱地围栏中圈养转变为使用储存的饲料和打包放牧，在冬季的几个月里，牛在牧场上呆了很长一段时间。在这些广阔的环境中过冬的牛暴露在长时间的寒冷和波动的天气模式中。早期对冷暴露牛的开创性工作是在环境室或室外围栏等受控条件下进行的，环境温度很少低于-10摄氏度。虽然对我们理解牛的冷生理至关重要，但我们对先前结果的解释和应用于当前生产系统存在局限性。这种理解的基础是测量个体动物干物质摄入量的能力。拟议的研究将使我们能够验证粪便近红外光谱作为一种可行的、非侵入性的方法，用于测量自由放养环境（越冬和牧场）中牛的个体动物摄入量。使用这种技术和其他新技术，包括行为生物识别技术和近红外热成像技术，将使我们能够提供关于牛在广泛的、无限制的越冬环境中的行为和代谢反应的新信息。这项工作将为制定更好的口粮配方和应对寒冷天气的动物管理策略提供必要的基础信息。研究结果还将提高我们在寒冷气候下减少养牛生产系统环境足迹的能力。该计划的一个主要组成部分将是培养高素质的人员，这些人员将利用他们对基本行为和生理过程的理解，将更好的做法和技术融入肉牛生产，特别是与粗养（牧场或牧场）系统有关的做法和技术。

In the last decade, management of cattle during the winter months has shifted from confinement in drylot pens to use of stock-piled forage and bale grazing where cattle are kept on pasture for significant periods of time during the winter months. Cattle wintered in these extensive environments are exposed to long periods of cold and fluctuating weather patterns. The early groundbreaking work on cold exposed cattle was conducted in controlled conditions such as environmental chambers or outdoor confinement pens in which ambient temperatures were rarely less than -10 degrees C. While critical to our understanding of cold physiology in cattle, there are limitations to our interpretation and application of previous results to current production systems. Fundamental to this understanding is the ability to measure individual animal dry matter intake. The proposed research will enable us to validate the use of fecal NIR spectra as a viable, non-invasive method for measurement of individual animal intake in cattle in free-ranging environments (overwintering and pasture). Use of this and other novel techniques including behavioural biometrics and near infrared thermography will enable us to provide new information regarding the behavioural and metabolic responses of cattle in extensive, non-confined overwintering environments. This work will provide the fundamental information required to develop better ration formulations and animal management strategies for cold weather. The results will also improve our ability to reduce the environmental footprint for cattle production systems in cold climates. A major component of this program will be the development of highly-qualified personnel who will use their understanding of basic behavioural and physiological processes to integrate better practices and technologies into beef cattle production, particularly as they relate to extensive (pasture or range-based) systems.