Abstract Recording grazing time is important because the time allocated for each grazing event is one of the limitations to achieving high intake levels. Grazing time can be measured via visual observation or, more recently, by devices calibrated for this purpose. The Kenz Lifecorder Plus (Suzuken Co. Ltda., Nagoya, Japan) has been used to record daily grazing time with high accuracy, but none of the previous studies have analyzed how pasture characteristics and grazing management influence the recording sensitivity of this device. Thus, the aim of this study was to evaluate the effect of pre-grazing herbage mass and season of the year on the activity level recorded by the Lifecorder Plus and its resulting threshold value used to determine a grazing event for dairy cows. A randomized 2 × 2 factorial design was used to evaluate the effect of two pre-grazing herbage masses (HM), medium herbage mass (MHM) and high herbage mass (HHM), in two seasons, winter (WIN) and spring (SPR), on the observed and predicted grazing time. In each period, two groups of six Holstein Friesian cows were fitted with a Lifecorder Plus in a collar attached to their neck. The pasture characteristics and observed and predicted grazing times were measured. There was no effect (P > 0.05) of HM on the observed grazing time. The grazing time in SPR was significantly higher (P 0.05) of HM on the threshold value. The threshold value for SPR was significantly higher (P

中文翻译：

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受放牧季节和牧草质量影响的单轴加速度计区分奶牛放牧活动的阈值

摘要 记录放牧时间很重要，因为为每个放牧事件分配的时间是实现高摄入量的限制之一。放牧时间可以通过目视观察或最近通过为此目的校准的设备来测量。Kenz Lifecorder Plus (Suzuken Co. Ltda., Nagoya, Japan) 已被用于高精度记录每日放牧时间，但之前的研究均未分析牧场特征和放牧管理如何影响该设备的记录灵敏度。因此，本研究的目的是评估放牧前牧草质量和一年中的季节对 Lifecorder Plus 记录的活动水平的影响，以及用于确定奶牛放牧事件的阈值。使用随机 2 × 2 因子设计来评估两个放牧前牧草群 (HM)、中等牧草群 (MHM) 和高牧草群 (HHM) 在冬季 (WIN) 和春季 (SPR) 两个季节的影响)，观察和预测的放牧时间。在每个时期，两组 6 头荷斯坦弗里斯兰奶牛都在脖子上安装了 Lifecorder Plus。测量了牧场特征以及观察到和预测的放牧时间。HM 对观察到的放牧时间没有影响（P > 0.05）。SPR 中的放牧时间在阈值上显着高于 HM（P<0.05）。SPR 的阈值显着更高（P 在每个时期，两组 6 头荷斯坦弗里斯兰奶牛都在脖子上安装了 Lifecorder Plus。测量了牧场特征以及观察到和预测的放牧时间。HM 对观察到的放牧时间没有影响（P > 0.05）。SPR 中的放牧时间在阈值上显着高于 HM（P<0.05）。SPR 的阈值显着更高（P 在每个时期，两组 6 头荷斯坦弗里斯兰奶牛都在脖子上安装了 Lifecorder Plus。测量了牧场特征以及观察到和预测的放牧时间。HM 对观察到的放牧时间没有影响（P > 0.05）。SPR 中的放牧时间在阈值上显着高于 HM（P<0.05）。SPR 的阈值显着更高（P