Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Koenigsweg 65, 14163 Berlin, Germany.
J Dairy Sci. 2013 May;96(5):3265-71. doi: 10.3168/jds.2012-6003. Epub 2013 Mar 15.
Lying behavior might indicate how the animal interacts with its environment and is an important indicator of cow and calf comfort. Measuring behavior can be time consuming; therefore, behavioral recording with the help of loggers has become common. Recently, the Hobo Pendant G data logger (Onset Computer Corp., Bourne, MA) was validated for measuring lying behavior in cows but no work to date has validated this logger for measuring lying behavior in calves. The objective of this study was to test the accuracy of the Hobo Pendant G data logger for measuring total lying time and frequency of lying bouts in dairy calves. In 2 experiments (experiment 1: thirty-seven 2-h observation periods; experiment 2: nineteen 24-h observation periods), we tested the effect of 2 different recording intervals, the effect of attachment to different legs, and the effect of removing short, potentially erroneous readings. We found an excellent relationship when comparing the 30-s and 60-s recording intervals. For total lying time and bout frequency, the highest correlation was found when the logger was attached to the hind legs and recording was conducted with a 60-s sampling interval. In experiment 2, average total lying time was 1,077 ± 54 min/24 h (18.0 ± 0.9h/24h), with an average frequency of 19.4 ± 4.5 bouts per day. Predictability, sensitivity, and specificity for experiment 2 were >97% using the 60-s recording interval and removing single readings of lying or standing from the data set compared with direct observation as reference. The data logger accurately measured total lying time and bout frequency when the sampling interval was ≤ 60 s and short readings of lying and standing up to 1 min were converted into the preceding behavior. The best results were achieved by attaching the logger to the right hind leg.
躺卧行为可能表明动物如何与环境相互作用，是牛只和牛犊舒适度的重要指标。行为测量可能很耗时；因此，借助记录器进行行为记录已经变得很常见。最近，Hobo Pendant G 数据记录器（Onset Computer Corp.，Bourne，MA）已被验证可用于测量奶牛的躺卧行为，但迄今为止尚无用于测量犊牛躺卧行为的记录器。本研究的目的是测试 Hobo Pendant G 数据记录器测量奶牛犊总躺卧时间和躺卧次数的准确性。在 2 项实验中（实验 1：37 个 2 小时观察期；实验 2：19 个 24 小时观察期），我们测试了 2 种不同记录间隔、不同腿部附着以及去除短时间、可能错误的读数的影响。当比较 30 秒和 60 秒记录间隔时，我们发现了极好的相关性。对于总躺卧时间和卧姿频率，当记录器连接到后腿并且以 60 秒的采样间隔进行记录时，相关性最高。在实验 2 中，平均总躺卧时间为 1077±54 分钟/24 小时（18.0±0.9 小时/24 小时），平均卧姿频率为 19.4±4.5 次/天。与直接观察作为参考相比，使用 60 秒记录间隔并从数据集删除单个躺卧或站立读数，实验 2 的预测性、灵敏度和特异性均>97%。当采样间隔≤60 秒且躺卧和站立的短读数持续时间长达 1 分钟时，数据记录器可准确测量总躺卧时间和卧姿频率，并将其转换为之前的行为。将记录器连接到右后腿可获得最佳结果。
