The purpose of this study was to define an extensive suite of feeding behavior traits in growing crossbred cattle and to investigate their phenotypic inter-relationships as well as relationships with other performance and efficiency traits. Time-series feeding behavior data, as well feed intake and live-weight records, were available for 624 growing crossbred cattle, of which 445 were steers and 179 were heifers. Feeding behavior repeatability estimates were calculated using linear mixed models. Additionally, partial Spearman correlations were estimated among 14 feeding behavior traits, as well as between feeding behavior with both performance and feed efficiency traits, using residuals retained from linear mixed models. The marginal contribution of several feeding behavior traits to the variability in metabolizable energy intake (MEI) was also determined. Repeatability estimates of 0.57, 0.36, and 0.48 were calculated for the number of feed events per day, the total time spent feeding per day and feeding rate, respectively. Cattle that ate more frequently each day ate at a faster rate and consumed less energy in each visit to the feed bunk. More efficient cattle fed less often per day and fed for a shorter duration per day; they also had a slower feeding rate and fed for longer in each visit to the feed bunk. Moreover, heavier cattle fed for a longer duration per day, had a faster feeding rate, but fed less often per day; heavier animals also fed first in the pen after fresh feed was offered. The number of feed events per day and feeding time per day together explained an additional 13.4 percentage points of the variability in MEI above that already explained by all of growth rate, live-weight, and backfat depth. The results from the present study suggest that several repeatable time-series related feeding behavior traits, that are less resource intensive to measure, may have a role as useful predictor traits of important but relatively difficult to record traits, such as feed intake and efficiency.

中文翻译：

---

杂种生长牛的摄食行为差异很大。

这项研究的目的是在成长中的杂交牛中定义一套广泛的喂养行为特征，并研究它们的表型间相互关系以及与其他性能和效率特征的关系。有624头正在生长的杂种牛，其中包括445头公牛和179头小母牛的时序饲喂行为数据，以及采食量和活重记录。使用线性混合模型计算进食行为的可重复性估计值。此外，使用线性混合模型保留的残差，估计了14种饲喂行为性状之间的部分Spearman相关性，以及具有性能和饲料效率性状的饲喂行为之间的部分相关性。还确定了几种进食行为性状对代谢能摄入量（MEI）变异性的边际贡献。对于每天的进食事件数，每天的总进食时间和进食速度，计算得出的重复性估计分别为0.57、0.36和0.48。每天吃得更多的牛以更快的速度进食，并且每次探访饲料铺时消耗的能量更少。效率更高的牛每天减少饲喂频率，每天饲喂时间较短；他们的喂食速度也较慢，每次到饲料铺时的喂食时间都更长。而且，较重的牛每天饲喂时间更长，饲喂速度更快，但每天饲喂次数较少。提供新鲜饲料后，较重的动物也要先用钢笔喂养。每天的进食事件数量和每天的进食时间共同解释了MEI变异性的另外13.4个百分点，高于所有增长率，活重和后脂肪深度所解释的。本研究的结果表明，一些可重复的与时间序列相关的进食行为特征，对资源的消耗较少，可以作为重要但相对难以记录的特征（如采食量和饲料效率）的有用的预测特征。