The use of differentially corrected global positioning system to monitor activities of cattle at pasture
The use of differentially corrected global positioning system to monitor activities of cattle at pasture
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DOI：
10.1016/j.applanim.2003.11.003
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发表时间：
2004-03-25
影响因子：
2.3
通讯作者：
Becker, K
中科院分区：
文献类型：
--
作者：
Schlecht, E;H端lsebusch, C;Becker, K
全球定位系统（GPS）技术越来越多地应用于畜牧业科学，以监测牧场的使用和跟踪路线，并经常与监测动物活动的设备相结合。由于GPS数据是在时间和空间上引用的，因此假设从GPS数据中得出的参数，如在规定的时间间隔内的第一个点和最后一个点之间的行进距离和空中距离，可以用来计算放牧动物的日常活动预算和每小时活动模式的可靠估计。1998年全年对在半干旱的尼日尔西部公共土地上放牧的14头泽布牛进行了牧场监测。人类每隔5分钟观察一次行为，同时利用安装在动物身上的GPS装置每隔10秒记录一次地理位置。随机选择30组联合观测和GPS数据，按季节分层，分为15个单独行程的校准和验证数据集。行走、放牧和休息的日常预算和每小时的活动模式在两个数据集之间没有显著差异。在两个数据集中，活动模式的季节性差异是相似的。在3 min时间间隔的GPS数据计算的几个参数中，行走距离、第一个和最后一个记录位置之间的最短距离、每个记录位置与第一个位置的平均距离以及第三个和第一个参数之间的比值被证明是行走、放牧和休息的最可靠的决定因素。从校准数据导出的线性判别函数正确分类了校准数据集中79%的观测值和验证数据集中71%的观测值。校正数据的静息、放牧和步行误差率分别为0.272、0.195和0.176，验证数据的误差率分别为0.419、0.267和0.231。由于GPS设备固有的定位误差，低速放牧和静止放牧是最难以区分的。对于540 min的平均放牧日，gps计算的日活动预算分别高估了8 min和6 min的休息时间和步行时间，而验证数据集的放牧时间被低估了14 min。具有亚米精度的GPS设备可以更清楚地区分低速放牧和休息。该研究证明了利用GPS记录计算放牧牛的日常活动预算和每小时活动模式的潜力。(C) 2003 Elsevier B.V.版权所有
Global positioning system (GPS) technology is increasingly applied in livestock science to monitor pasture use and tracking routes, and is often combined with equipment for monitoring animal activity. As GPS data are referenced in time and space, it is hypothesised that parameters derived there from, such as distance travelled and aerial distance between the first and last point of a defined time interval, can be used to compute reliable estimates of daily activity budgets and hourly activity patterns of grazing animals.Fourteen Zebu cows grazing communal lands in semiarid western Niger were monitored on pasture throughout 1998. Observation of behaviour by man at intervals of 5 min was accompanied by logging geographical positions at intervals of 10 s using GPS units mounted on the animals. Thirty sets of combined observation and GPS data were randomly selected, stratified by season and split into a calibration and a validation data set of 15 individual itineraries each.Daily budgets and hourly patterns of the activities walking, grazing and resting did not differ significantly between the two data sets. Seasonal differences in activity patterns were similar in the two data sets. Among several parameters calculated from GPS data for 3 min time intervals, distance travelled, shortest distance between the first and the last logged position, average distance of each logged position from the first position and the ratio between the third and the first parameter proved to be the most reliable determinants for walking, grazing and resting. The linear discriminant functions derived from the calibration data correctly classified 79% of all observations in the calibration data set and 71% in the validation data set. Error count rates for resting, grazing and walking were 0.272, 0.195 and 0.176 for the calibration data and 0.419, 0.267 and 0.231 for the validation data. Grazing at low pace and resting were most difficult to differentiate due to the inherent location error of the GPS device. For the average grazing day of 540 min, the GPS-derived daily activity budget overestimated resting and walking time by 8 and 6 min, respectively, while grazing time was underestimated by 14 min for the validation data set. Evidence is provided that GPS devices with submeter accuracy will allow distinguishing more clearly between grazing at low pace and resting.The study demonstrates the potential to compute reasonable estimates of daily activity budgets and hourly activity patterns of grazing cattle from GPS recordings. (C) 2003 Elsevier B.V. All rights reserved.