Abstract We validated the accuracy of two commercially available activity loggers for cattle in determining lying and standing durations, number of lying bouts and number of steps in growing lambs. Ten growing lambs divided into two weight classes were fitted with an IceTag on the right hind leg and an IceQube on the left hind leg. The IceTag reports activity per second, whereas the IceQube reports activity in 15-min periods. To enable comparison between loggers, IceTag data were also summarized in 15-min periods. Computed indications for the start of a lying bout of durations >10 s and >30 s was performed to enable filtering of lying bout data. Analyses of the lambs body posture and number of steps per second from 50 h of video recordings were used as a gold standard to determine the accuracy of the two loggers. Two observers scored the two different groups and inter-observer reliability was consistent for standing, lying and number of lying bouts (κ = 0.99). However, the observers defined step count differently and no agreement was found (κ = -0.05; -0.11). Based on Bland-Altman comparison both loggers can be used to record standing and lying time. The positive predictive value (PPV), sensitivity and specificity of the IceTag compared to video recordings per second for standing and lying were all > 91.5 %. The IceTag showed a poor PPV (

中文翻译：

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验证加速计以自动记录羔羊生长中的姿势和步数

摘要 我们验证了两种市售的牛活动记录仪在确定羔羊躺卧和站立持续时间、躺卧次数和步数方面的准确性。十只分为两个体重等级的成长羔羊在右后腿上安装了 IceTag，在左后腿上安装了 IceQube。IceTag 报告每秒活动，而 IceQube 报告每 15 分钟的活动。为了能够在记录器之间进行比较，IceTag 数据还以 15 分钟为单位进行汇总。对持续时间 > 10 s 和 > 30 s 的谎言回合开始进行计算指示，以实现对谎言回合数据的过滤。从 50 小时的视频记录中分析羔羊的身体姿势和每秒步数被用作确定两个记录器准确性的黄金标准。两名观察者对两个不同的组进行评分，并且观察者间的可靠性在站立、躺卧和躺卧次数方面是一致的 (κ = 0.99)。然而，观察者对步数的定义不同，没有发现一致性（κ = -0.05；-0.11）。根据 Bland-Altman 比较，两种记录器都可用于记录站立和躺下的时间。与每秒站立和躺下的视频记录相比，IceTag 的阳性预测值 (PPV)、敏感性和特异性均 > 91.5 %。IceTag 的 PPV 很差（与每秒站立和躺下的视频记录相比，IceTag 的阳性预测值 (PPV)、敏感性和特异性均 > 91.5 %。IceTag 的 PPV 很差（与每秒站立和躺下的视频记录相比，IceTag 的阳性预测值 (PPV)、敏感性和特异性均 > 91.5 %。IceTag 的 PPV 很差（