Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin D04 W6F6, Ireland.
Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin D04 W6F6, Ireland.
J Dairy Sci. 2024 May;107(5):3197-3206. doi: 10.3168/jds.2023-23928. Epub 2023 Dec 14.
Lameness is an important production disease in dairy cows worldwide and has detrimental effects on cows' welfare, production, and reproductive performance, thus affecting the sustainability of dairy farming. Timely and effective detection of lameness allows for effective treatment, minimizing progression of disease, and maximizing the prognosis of recovery. Mobility scoring (MSc) is a 4 point (0-3) visual lameness scoring system that is the industry standard in several countries. However, few studies have examined the sensitivity (Se) and specificity (Sp) of MSc to detect foot lesions. The aim of this observational study was to determine the Se and Sp of MSc to detect foot lesions in dairy cattle in a pasture-based system. Five hundred ninety-five primi- and multiparous cows were randomly selected from 12 commercial Irish dairy farms and recruited for the study. Recruited cows were mobility scored and passed through a foot-paring crate where all 4 feet were lifted for examination. The team recorded the anatomical location and severity of any foot lesions present based on appearance only. Then, based on the type and severity of the lesions present, cows were classified according to 3 case definitions case definition 1: Any lesion present; case definition 2: Moderate lesions present (excluding minor lesions expected to have a low probability of affecting gait); and case definition 3: Severe lesions present (only including lesions most likely to result in a detectable gait abnormality). Sensitivity and Sp of MSc was calculated based on a threshold of MSc ≥2, defined as impaired (MSc = 2) or severely impaired (MSc = 3) mobility for each of the 3 case definitions, at the overall level and disaggregated by parity. The overall cow-level lesion prevalence based on the case definition 1 was 0.54 with significant between-herd variation. The overall Se and Sp of MSc for the detection of foot lesions were 0.18 and 0.96, 0.35 and 0.94, 0.43 and 0.94 for the case definitions 1, 2, and 3, respectively. Our findings showed poor Se, but high Sp of MSc for the detection of cows with foot lesions in a pasture-based system.
跛行是全球奶牛养殖业中的一种重要生产疾病，对奶牛的福利、生产和繁殖性能都有不利影响，从而影响了奶牛养殖业的可持续性。及时有效地发现跛行可以进行有效的治疗，最大限度地减少疾病的进展，并最大限度地提高恢复的预后。运动评分（MSc）是一种 4 分（0-3）的视觉跛行评分系统，在几个国家是行业标准。然而，很少有研究检查 MSc 检测足部病变的敏感性（Se）和特异性（Sp）。本观察性研究的目的是确定 MSc 在牧场系统中检测奶牛足部病变的 Se 和 Sp。从 12 家爱尔兰商业奶牛场中随机选择了 595 头初产和经产奶牛参加这项研究。招募的奶牛进行了运动评分，并通过一个脚部修剪箱，将所有 4 只脚抬起进行检查。团队仅根据外观记录任何足部病变的解剖位置和严重程度。然后，根据病变的类型和严重程度，根据 3 种病例定义对奶牛进行分类：病例定义 1：存在任何病变；病例定义 2：存在中度病变（不包括预期对步态影响较小的轻度病变）；病例定义 3：存在严重病变（仅包括最有可能导致可检测步态异常的病变）。根据 MSc≥2 的阈值，计算 MSc 的敏感性和特异性，定义为受损（MSc=2）或严重受损（MSc=3）运动能力，用于 3 种病例定义中的每一种，在整体水平上，并按胎次进行细分。基于病例定义 1 的整体奶牛水平病变患病率为 0.54，存在显著的 herd 间变异。基于病例定义 1，MSc 检测足部病变的整体敏感性和特异性分别为 0.18 和 0.96、0.35 和 0.94、0.43 和 0.94。我们的研究结果表明，在牧场系统中，MSc 检测跛行奶牛的敏感性较低，但特异性较高。
