小牛行为与其早期生长密切相关,生产性能,和健康表现。连续行为记录是用于监测动物行为的最准确但耗时的方法,因此,通常采用瞬时抽样方法来最大程度地减少动物研究中量化行为观察所需的时间。此外,获得准确信息以估计荷斯坦奶牛行为所需的最佳采样间隔仍然未知。我们的主要目标是确定最佳采样间隔,以监测断奶前和断奶期间荷斯坦奶牛的行为,以提高效率,同时保持可靠性。次要目标是描述他们的行为模式。Rumination,说谎,站立,和18只小牛的非营养口腔行为(NNOB)数据(观察时间:360小时/小牛,总共6,480h)连续记录15d(在1、3、6、9和12周龄时3d)。将连续行为数据与5s时的瞬时采样进行比较,10s,15s,30s,1分钟,3分钟,5分钟,10分钟,15分钟,30分钟,和60分钟的间隔。如果采样间隔符合4个标准,则认为它们是准确的:确定系数≥0.90(即,与真实值密切相关),斜率=1,截距=0(即,他们没有高估或低估真实价值),相对误差<10%。最佳采样间隔被认为是符合准确监测标准的11个采样间隔中的最高采样间隔。不出所料,随着采样间隔的增加,连续记录和瞬时采样之间的线性关系强度降低。不同行为的结果不同,带着沉思,说谎,站立,NNOB在3分钟的瞬时记录下是可靠的,10分钟,10分钟,断奶前(1、3和6周)和10分钟,10分钟,15分钟,断奶后3分钟(9周和12周)。就行为模式而言,说谎时间减少,而沉思,站立,NNOB时间随年龄增长而增加。断奶后,执行这些行为所花费的时间没有显著变化。此外,沉思行为模式在wk6后变得稳定,在早晨喂食后逐渐减少,主要发生在早晨。总之,瞬时采样是一种可靠的监测奶牛行为的方法,但是应根据不同的年龄和管理条件选择最佳的采样间隔。
Calf behavior is closely related to its early growth, production performance, and health performance. Continuous behavior recording is the most accurate but also time-consuming method used for monitoring animal behaviors, so the instantaneous sampling method is often adopted to minimize the time required to quantify behavioral observations in animal studies. Moreover, the optimal sampling intervals required to yield accurate information for estimating Holstein dairy calves\' behaviors are still unknown. Our primary objective was to determine the most optimal sampling intervals for monitoring behaviors of Holstein dairy calves during preweaning and weaning periods to improve efficiency while maintaining reliability. The secondary objective was to describe their behavioral patterns. Rumination, lying, standing, and non-nutritive oral behavior (NNOB) data of 18 calves (observation time: 360 h/calf, 6,480 h in total) were continuously recorded for 15 d (3 d at 1, 3, 6, 9, and 12 wk of age). The continuous behavioral data were compared with instantaneous sampling at 5 s, 10 s, 15 s, 30 s,1 min, 3 min, 5 min, 10 min, 15 min, 30 min, and 60 min intervals. Sampling intervals were considered accurate if they met 4 criteria: coefficient of determination ≥0.90 (i.e., strongly related to true values), slope = 1, intercept = 0 (i.e., they did not over- or underestimate true values), and relative error <10%. The most optimal sampling interval was considered the highest sampling interval among the 11 sampling intervals that meet the criteria for accurate monitoring. As expected, the strength of the linear relationship between the continuous recording and instantaneous sampling decreased as the sampling intervals increased. The results varied across the different behaviors, with rumination, lying, standing, and NNOB being reliable at instantaneous recordings of 3 min, 10 min, 10 min, and 1 min for the preweaning period (1, 3, and 6 wk of age) and 10 min, 10 min, 15 min, and 3 min for the postweaning period (9 and 12 wk of age). In terms of behavioral patterns, lying time decreased, whereas rumination, standing, and NNOB time increased with age. After weaning, no significant changes in time spent performing these behaviors. Additionally, the rumination behavioral pattern becomes stable after wk 6 with decreasing after the morning feeding and occurring mainly in the morning. In conclusion, instantaneous sampling is a reliable method for monitoring the behaviors of dairy calves, but the optimal sampling intervals should be selected based on different ages and management conditions.