Precision Livestock Farming (PLF) Lab, Institute of Agricultural Engineering, Agricultural Research Organization - ARO, Volcani Center, 68 Hamaccabim Road, Rishon LeZion 7505101, Israel; Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel.
Department of Engineering for Livestock Management, Leibniz Institute for Agricultural Engineering and Bio Economy - ATB, Potsdam 14469, Germany; Institute of Animal Hygiene and Environmental Health, College of Veterinary Medicine, Free University Berlin, Berlin 14163, Germany.
Animal. 2021 Feb;15(2):100093. doi: 10.1016/j.animal.2020.100093. Epub 2020 Dec 29.
Technological progress enables individual cow's temperatures to be measured in real time, using a bolus sensor inserted into the rumen (reticulorumen). However, current cooling systems often work at a constant schedule based on the ambient temperature and not on monitoring the animal itself. This study hypothesized that tailoring the cooling management to the cow's thermal reaction can mitigate heat stress. We propose a dynamic cooling system based on in vivo temperature sensors (boluses). Thus, cooling can be activated as needed and is thus most efficacious. A total of 30 lactating cows were randomly assigned to one of two groups; the groups received two different evaporative cooling regimes. A control group received cooling sessions on a preset time-based schedule, the method commonly used in farms; and an experimental group, which received the sensor-based (SB) cooling regime. Sensor-based was changed weekly according to the cow's reaction, as reflected in the changes in body temperatures from the previous week, as measured by reticulorumen boluses. The two treatment groups of cows had similar milk yields (44.7 kg/d), but those in the experimental group had higher milk fat (3.65 vs 3.43%), higher milk protein (3.23 vs 3.13%), higher energy corrected milk (ECM, 42.84 vs 41.48 kg/d), higher fat corrected milk 4%; (42.76 vs 41.34 kg/d), and shorter heat stress duration (5.03 vs 9.46 h/day) comparing to the control. Dry matter intake was higher in the experimental group. Daily visits to the feed trough were less frequent, with each visit lasting longer. The sensor-based cooling regime may be an effective tool to detect and ease heat stress in high-producing dairy cows during transitional seasons when heat load can become severe in arid and semi-arid zones.
技术进步使得可以使用插入瘤胃（网胃）的块状传感器实时测量每头牛的体温。然而，当前的冷却系统通常根据环境温度而不是监测动物本身来按固定时间表运行。本研究假设根据牛的热反应来定制冷却管理可以减轻热应激。我们提出了一种基于体内温度传感器（块状物）的动态冷却系统。因此，可以根据需要激活冷却，从而最有效。共有 30 头泌乳奶牛被随机分配到两组中的一组；两组接受两种不同的蒸发冷却方案。对照组根据预设的时间基础时间表进行冷却，这是农场中常用的方法；实验组则接受基于传感器的（SB）冷却方案。根据前一周体温变化反映的牛的反应，每周根据传感器变化调整基于传感器的冷却方案。两组奶牛的产奶量相似（44.7 公斤/天），但实验组的奶牛产奶量更高（3.65 比 3.43%）、乳脂更高（3.23 比 3.13%）、能量校正奶更高（42.84 比 41.48 公斤/天）、脂肪校正奶高 4%（42.76 比 41.34 公斤/天），并且与对照组相比，热应激持续时间更短（5.03 比 9.46 小时/天）。实验组的干物质摄入量更高。去饲料槽的次数更少，每次停留时间更长。基于传感器的冷却方案可能是一种有效工具，可以在过渡季节检测和缓解高产品种奶牛的热应激，在干旱和半干旱地区，热负荷可能会变得很严重。
