Chapinal N, de Passillé A M, Weary D M, von Keyserlingk M A G, Rushen J
University of British Columbia, Vancouver, British Columbia, Canada.
J Dairy Sci. 2009 Sep;92(9):4365-74. doi: 10.3168/jds.2009-2115.
The objective was to determine whether changes in the different components of gait, walking speed, and lying behavior were associated with hoof pathologies in lactating Holstein cows. In experiment 1, 53 cows had their gait scored, their walking speed estimated, and their lying behavior monitored before clinical assessment of the hooves. Multiparous cows with ulcers scored higher than cows without ulcers for overall gait score [numerical rating score (NRS); 3.3 +/- 0.2 vs. 2.8 +/- 0.2], back arch, joint flexion, asymmetric steps, and reluctance to bear weight. Although cows with ulcers did not walk more slowly than cows without ulcers (1.4 m/s), they spent more time lying down (827.8 +/- 29.1 vs. 738.2 +/- 15.5 min/d) because of longer lying bouts (93.3 +/- 5.9 vs. 79.7 +/- 3.4 min). In experiment 2, 47 cows were monitored for hoof health and changes in gait score from 4 wk before to 24 wk after calving. Differences were found after calving between cows that developed an ulcer and cows that did not for NRS (3.1 +/- 0.1 vs. 2.35 +/- 0.1), back arch, joint flexion, asymmetric steps, and reluctance to bear weight. Numerical rating score, back arch, and asymmetric steps were able to discriminate cows with ulcers at least 4 wk before the diagnosis. Cows that developed a sole ulcer had a faster decline in lying time during the periparturient period and a faster increase beginning in wk 2 after calving. The NRS was a more consistent predictor of sole ulcers than lying behavior or speed. The NRS was able to discriminate cows with ulcers across studies at a high intraobserver accuracy and reasonable specificity and was able to predict the presence of ulcers at least 4 wk before diagnosis. Abduction/adduction of the rear legs, head bob, and tracking-up did not consistently discriminate cows with ulcers, and we suggest that these measures are less useful for on farm gait assessment. Compared with the other gait attributes, back arch, joint flexion, asymmetric steps, and reluctance to bear weight best predicted the presence of sole ulcers.
目的是确定泌乳期荷斯坦奶牛步态的不同组成部分、行走速度和躺卧行为的变化是否与蹄部病变相关。在实验1中，53头奶牛在进行蹄部临床评估之前，先对其步态进行评分、估计其行走速度并监测其躺卧行为。患有溃疡的经产奶牛在总体步态评分[数字评分量表（NRS）；3.3±0.2对2.8±0.2]、背部拱起、关节屈曲、不对称步幅以及负重意愿方面的得分高于未患溃疡的奶牛。虽然患有溃疡的奶牛行走速度并不比未患溃疡的奶牛慢（1.4米/秒），但由于躺卧时间更长（827.8±29.1对738.2±15.5分钟/天），它们躺卧的时间更多，单次躺卧时间更长（93.3±5.9对79.7±3.4分钟）。在实验2中，对47头奶牛在产犊前4周直至产犊后24周期间的蹄部健康状况和步态评分变化进行了监测。产犊后，患溃疡的奶牛与未患溃疡的奶牛在NRS（3.1±0.1对2.35±0.1）、背部拱起、关节屈曲、不对称步幅以及负重意愿方面存在差异。数字评分量表、背部拱起和不对称步幅能够在诊断前至少4周区分出患有溃疡的奶牛。发生蹄底溃疡的奶牛在围产期躺卧时间下降更快，在产犊后第2周开始增加更快。与躺卧行为或速度相比，NRS是蹄底溃疡更一致的预测指标。在不同研究中，NRS能够以较高的观察者内准确性和合理的特异性区分出患有溃疡的奶牛，并且能够在诊断前至少4周预测溃疡的存在。后腿外展/内收、头部摆动和跟进行走并不能始终区分出患有溃疡的奶牛，我们认为这些指标在农场步态评估中用处较小。与其他步态特征相比，背部拱起、关节屈曲、不对称步幅和负重意愿最能预测蹄底溃疡的存在。
