Olsen Hannah E, Anderson Karly N, Creutzinger Katherine C, Vogel Kurt D
Department of Animal and Food Science, University of Wisconsin-River Falls, River Falls 54022.
Department of Animal Science, University of Nebraska-Lincoln, Lincoln 68583.
JDS Commun. 2023 Jan 2;4(4):265-268. doi: 10.3168/jdsc.2022-0254. eCollection 2023 Jul.
Dairy cows are regularly handled when moved to the milking parlor and during other routine procedures. Low-stress handling methods are important in avoiding negative welfare states for dairy cattle. Tail twisting is used by some handlers to prompt cattle movement. However, when used inappropriately with excessive force, tail twisting can lead to a broken tail. The aim of this cross-sectional study was to determine cow-level factors that may be associated with the prevalence of broken tails in dairy cattle. A subset of 229 Holstein dairy cows (68 primiparous and 161 multiparous) at a single dairy were assessed for broken tails from the larger herd (N = 1,356). Tails were visually assessed for the presence of fractures by a single trained observer. A tail was classified as unfractured if it laid straight when at rest and as fractured if there were deviations in the tail when at rest. Poisson regression models were used to identify associations between cow-level characteristics and broken tails and compute adjusted prevalence ratios (PR). The prevalence of broken tails was 45.8% (105/229) at the time of assessment. Multiparous cows had a greater prevalence of broken tails than primiparous cows [PR = 1.70; 95% confidence interval (CI): 1.11-2.59]. The prevalence of broken tails was also greater for cows treated for mastitis ≥2 times than cows treated once for mastitis (PR = 1.84; 95% CI: 1.08-3.13) and cows never treated for mastitis (PR = 1.36; 95% CI: 1.02-1.82). Results from this study indicated that the longer a cow was present on the farm and the more times she was treated for mastitis, the more likely she was to experience a broken tail. These findings suggest that the relationship between dairy cow handling, health, and welfare is a multifactorial issue.
奶牛在进入挤奶厅以及进行其他常规操作时会经常被处理。低压力处理方法对于避免奶牛出现负面福利状态很重要。一些饲养员会通过扭尾巴来促使奶牛移动。然而，若使用不当且用力过度，扭尾巴可能会导致尾巴骨折。这项横断面研究的目的是确定可能与奶牛尾巴骨折患病率相关的奶牛个体因素。对某一奶牛场中229头荷斯坦奶牛（68头初产牛和161头经产牛）组成的一个子集进行了评估，这些奶牛来自规模更大的牛群（N = 1356）。由一名经过培训的观察者通过目视评估尾巴是否存在骨折情况。如果尾巴在静止时伸直，则分类为未骨折；如果尾巴在静止时有偏差，则分类为骨折。使用泊松回归模型来确定奶牛个体特征与尾巴骨折之间的关联，并计算调整后的患病率比值（PR）。在评估时，尾巴骨折的患病率为45.8%（105/229）。经产牛尾巴骨折的患病率高于初产牛[PR = 1.70；95%置信区间（CI）：1.11 - 2.59]。与仅接受过一次乳腺炎治疗的奶牛相比，接受过≥2次乳腺炎治疗的奶牛尾巴骨折的患病率也更高（PR = 1.84；95% CI：1.08 - 3.13），且高于从未接受过乳腺炎治疗的奶牛（PR = 1.36；95% CI：1.02 - 1.82）。这项研究的结果表明，奶牛在农场的饲养时间越长以及接受乳腺炎治疗的次数越多，其尾巴骨折的可能性就越大。这些发现表明，奶牛处理、健康和福利之间的关系是一个多因素问题。
