Institute of Nutritional Physiology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.
ITIN + HOCH GmbH Feeding Technology, Liestal, Switzerland.
J Anim Sci. 2018 Nov 21;96(11):4483-4489. doi: 10.1093/jas/sky337.
The pressure-based noseband sensor system (RWS: RumiWatch System; ITIN + HOCH GmbH Feeding Technology, Liestal, Switzerland) has recently been validated for the measurement of rumination time in mature cows. We aimed in this study at developing a similar pressure-based system for monitoring rumination in young dairy calves. To this end, a vegetable oil-filled silicon tube with a built-in pressure sensor (outer diameter 5.7 mm, length 38 cm) was attached to the noseband of a calf halter. In contrast to the RWS developed for mature cows, the accelerometer, the battery, the data logger, and the SD card of the RWS were integrated into 1 box to reduce the weight of the RWS to 0.35 kg. The box was attached to the halter so that it was located behind the right ear of the calf. Ten pre-weaned German Holstein calves (49-106 kg BW and 33-63 days of age) were equipped with the RWS. Calves were milk-fed thrice a day and offered hay and commercial starter for ad libitum intake. In parallel, animals were monitored by a video camera connected to a video recorder for 12 h. Two independent observers assessed the video records to obtain a reliable gold standard for the evaluation of the newly developed RWS. Data obtained by either RWS or visual video observation were processed as min rumination per h, yielding a total of 120 pairs of values (12 pairs per animal) for regression analysis. Assessment of 2 independent observers were highly correlated (r = 0.99). Results indicated relatively low random error between results obtained from the RWS (on y-axis) and video observations (on x-axis) (R2 = 0.82). However, the intercept of the regression line (y = 7.70 + 0.64 x) was significantly different from zero (P < 0.01) and the 95% confidence interval of the slope (0.79-0.94) did not include the value of 1. This translates to a significant systemic error resulting in overestimation of rumination time which is attributable to nutritive and nonnutritive oral activities that almost exclusively lasted for up to 10 min. Exclusion of false positive rumination signals lasting less than 10 or 5 consecutive min from the analysis reduced the random and systemic errors of the model (R2 = 0.86 and 0.93, respectively). We conclude that the newly developed RWS can be used to provide accurate measurement of rumination time in young calves. However, an extra programmed algorithm in the evaluation software is recommended to make the system more user-friendly for measurements on calves.
压力式鼻带传感器系统（RWS：RumiWatch 系统；ITIN + HOCH 喂养技术公司，利斯塔尔，瑞士）最近已被验证可用于测量成熟奶牛的反刍时间。我们旨在本研究中开发一种类似的压力式系统，用于监测幼奶牛的反刍。为此，将一个内置压力传感器的注满植物油的硅管（外径 5.7 毫米，长 38 厘米）附接到小牛鼻带上。与为成熟奶牛开发的 RWS 相比，RWS 的加速度计、电池、数据记录器和 SD 卡集成到 1 个盒子中，将 RWS 的重量减轻至 0.35 公斤。该盒子附接到鼻带上，以便位于小牛右耳后面。10 头未断奶的德国荷斯坦小牛（49-106 公斤 BW 和 33-63 天龄）配备了 RWS。小牛每天三次喂奶，并提供干草和商业起始料供自由采食。同时，动物通过连接到录像机的摄像机进行 12 小时的监测。两名独立观察员评估视频记录，为新开发的 RWS 的评估获得可靠的黄金标准。通过 RWS 或视频观察获得的数据均处理为每小时反刍次数，为回归分析提供了总共 120 对值（每个动物 12 对）。两名独立观察员的评估结果高度相关（r = 0.99）。结果表明，RWS（y 轴）和视频观察（x 轴）获得的结果之间的随机误差相对较低（R2 = 0.82）。然而，回归线的截距（y = 7.70 + 0.64 x）与零显著不同（P < 0.01），斜率的 95%置信区间（0.79-0.94）不包括 1。这意味着存在系统误差，导致反刍时间的高估，这归因于营养性和非营养性口腔活动，这些活动几乎仅持续 10 分钟。从分析中排除持续时间小于 10 或 5 分钟的假阳性反刍信号可降低模型的随机和系统误差（R2 分别为 0.86 和 0.93）。我们得出结论，新开发的 RWS 可用于准确测量幼小牛的反刍时间。然而，建议在评估软件中添加额外的编程算法，以提高系统对小牛测量的易用性。
