Department of Animal Production, Federal University of Goiás, Av. Esperança S/N, Chácaras de Recreio Samambaia, 74690-900, Goiânia, Goiás, Brazil.
Department of Animal Production, Federal University of Goiás, Av. Esperança S/N, Chácaras de Recreio Samambaia, 74690-900, Goiânia, Goiás, Brazil.
J Therm Biol. 2021 Apr;97:102871. doi: 10.1016/j.jtherbio.2021.102871. Epub 2021 Feb 10.
With the expanding use of thermal assessment techniques in beef cattle, infrared thermography has become a promising tool for assessing the environment for animal thermal comfort. Goals of this study were: (1) to evaluate cattle thermal comfort in agroforestry systems with different shade availability (2) to verify the spatiotemporal variations of infrared temperature inside agroforestry systems, and; (3) to test infrared thermography as a potential tool to assess animal thermal comfort indices in agroforestry systems. A trial was carried out between June 2015 and February 2016, covering Central-Brazil's dry winter and rainy summer seasons, respectively. The experimental area of Embrapa Beef Cattle is located in Campo Grande (Mato Grosso do Sul), coordinates 20°24'53″ S, 54°42'26″ W and 558 m altitude. The 12 ha plot has two agroforestry systems varying shade availability. Traditional Black Globe Temperature and Humidity Index, Heat Load Index and Radiation Thermal Load were determined, from measurements using digital thermo-hygrometers, with datalogger. Surface temperature and humidity of tree canopies and pasture were determined using an infrared thermographic camera. Results show spatiotemporal variations in infrared temperature. This means that the environment inside agroforestry systems is not homogeneously comfortable for cattle, and the system with the lowest shade availability has the greatest heat accumulation area. Weak to strong associations were identified between infrared variables and thermal comfort indices (0.08 = r ≤ 0.75). Positive relationships were also obtained and equally well explained by the Black Globe Temperature and Humidity Index and Heat Load Index (0.55 = R ≤ 0.94). We conclude that infrared thermography can be used as a tool to assess thermal comfort indices in agroforestry systems and to determine onset of animal thermal stress from environment and heat body accumulation.
随着热评估技术在肉牛中的广泛应用，红外热成像已成为评估动物热舒适环境的有前途的工具。本研究的目的是：（1）评估具有不同遮荫条件的农林复合系统中的牛的热舒适度；（2）验证农林复合系统内红外温度的时空变化；（3）测试红外热成像作为评估农林复合系统中动物热舒适度指数的潜在工具。该试验于 2015 年 6 月至 2016 年 2 月进行，分别涵盖了巴西中部的干燥冬季和雨季。试验场位于南马托格罗索州的 Campo Grande（坎波格兰德），坐标为 20°24'53″ S、54°42'26″ W 和 558 米海拔。12 公顷的试验区有两种不同遮荫条件的农林复合系统。通过数字温湿度计和数据记录仪，使用传统的黑球温度和湿度指数、热负荷指数和辐射热负荷来确定传统的黑球温度和湿度指数、热负荷指数和辐射热负荷。使用红外热像仪确定树冠和牧场的表面温度和湿度。结果表明，红外温度存在时空变化。这意味着农林复合系统内的环境对牛来说并不完全舒适，遮荫条件最低的系统具有最大的热量积累区域。红外变量与热舒适度指数之间存在弱到强的关联（0.08=r≤0.75）。还获得了黑球温度和湿度指数和热负荷指数（0.55=R≤0.94）的正相关关系，并得到了同样良好的解释。我们得出结论，红外热成像可用于评估农林复合系统中的热舒适度指数，并从环境和体热积累方面确定动物热应激的发生。
