Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, SE-75189 Uppsala, Sweden; Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden.
Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden; Växa Sverige, SE-10425 Stockholm, Sweden.
J Dairy Sci. 2020 Dec;103(12):11736-11749. doi: 10.3168/jds.2019-17935. Epub 2020 Oct 9.
Udder cleft dermatitis (UCD) is a common skin condition in Swedish dairy cows, affecting the anterior parts of the udder. The main objective of this study was to investigate incidence rate and duration of UCD in a 1-yr longitudinal study. Other objectives were to investigate risk factors for transitions from being healthy to having mild or severe UCD, and from having mild UCD to having severe UCD, and associations between UCD and clinical mastitis, somatic cell count (SCC) and hock lesions. Seven herds were included in the study and visited 9 times each at 6-wk intervals. At the visits, mild and severe UCD lesions, hock lesions, udder conformation traits, and hygiene scores were registered for each cow milked in the milking parlor. Information on breed, parity, days in milk (DIM), results from test milkings (milk production, SCC, and urea level), and veterinary treatments was also obtained. A UCD case was defined as one or several consecutive observations of UCD. The incidence and duration of UCD were described. Mixed-effect logistic regression models were used to analyze associations between potential risk factors and transitions to any type of UCD. Separate risk factor analyses were performed for transitions to mild and severe UCD. Associations with SCC, mastitis, and hock lesions were also analyzed with mixed-effect logistic regression models. The mean overall incidence of new UCD cases for all visits and herds was 0.5 cases per cow-year at risk. Risk factors associated with a higher risk of a transition to any type of UCD and mild UCD were breed (Swedish Red vs. Swedish Holstein), an indentation or fold at the fore udder attachment, and increasing DIM. In addition, a low milk urea level was associated with a lower risk of transition to any type of and mild UCD. Cows with previous mild UCD and high-yielding cows had increased risk for a transition to severe UCD. Cows that had an observed transition to severe UCD had an increased risk of veterinary-treated clinical mastitis within 6 wk after the UCD observation. No associations were found between UCD and SCC or hock lesions. The median observed duration of a UCD case was 12 wk, but most cases did not have an observed start or end during the study period. The observed duration of cases including severe UCD was longer than for cases involving only mild UCD. The high incidence and often long duration of UCD emphasize the need for preventive measures and treatment strategies.
奶牛乳房皱裂性皮炎（udder cleft dermatitis，UCD）是瑞典奶牛的一种常见皮肤疾病，主要影响乳房的前半部分。本研究的主要目的是在为期 1 年的纵向研究中调查 UCD 的发病率和持续时间。其他目的是调查从健康状态到轻度或重度 UCD 以及从轻度 UCD 到重度 UCD 的转变的风险因素，以及 UCD 与临床乳腺炎、体细胞计数（Somatic Cell Count，SCC）和跗关节病变之间的关系。本研究纳入了 7 个牛群，每个牛群在 6 周的间隔内进行了 9 次访问。在每次访问时，为在挤奶厅中挤奶的每头奶牛记录轻度和重度 UCD 病变、跗关节病变、乳房形态特征和卫生评分。还获得了关于品种、胎次、泌乳天数（days in milk，DIM）、测试挤奶的结果（产奶量、SCC 和尿素水平）和兽医治疗的信息。UCD 病例定义为连续观察到 1 次或多次 UCD。描述了 UCD 的发病率和持续时间。使用混合效应逻辑回归模型分析了潜在风险因素与任何类型 UCD 转变之间的关系。分别对向轻度和重度 UCD 的转变进行了风险因素分析。还使用混合效应逻辑回归模型分析了与 SCC、乳腺炎和跗关节病变的关联。所有访问和牛群的总新 UCD 病例的平均发生率为每头奶牛每年 0.5 例。与任何类型 UCD 和轻度 UCD 转变风险增加相关的风险因素包括品种（瑞典红牛 vs. 瑞典荷斯坦牛）、前乳房附着处的凹陷或褶皱以及 DIM 的增加。此外，低牛奶尿素水平与任何类型和轻度 UCD 转变的风险降低相关。有轻度 UCD 病史的奶牛和高产量奶牛发生重度 UCD 转变的风险增加。观察到重度 UCD 转变的奶牛在 UCD 观察后 6 周内发生兽医治疗的临床乳腺炎的风险增加。UCD 与 SCC 或跗关节病变之间没有关联。UCD 病例的观察持续时间中位数为 12 周，但大多数病例在研究期间没有观察到开始或结束。包括重度 UCD 的病例的观察持续时间长于仅涉及轻度 UCD 的病例。UCD 的高发病率和通常较长的持续时间强调了需要采取预防措施和治疗策略。
