Pedersen Lars, Houe Hans, Rattenborg Erik, Nielsen Liza Rosenbaum
Department of Veterinary and Animal Sciences, Section for Animal Health and Welfare, University of Copenhagen, Frederiksberg, Denmark.
SEGES Innovation P/S, Animal Health and Welfare, Cattle Livestock, Aarhus, Denmark.
Front Vet Sci. 2025 May 19;12:1566380. doi: 10.3389/fvets.2025.1566380. eCollection 2025.
Dublin (. Dublin) is a cattle-adapted bacterium with enzootic occurrence in cattle populations of many countries. Preventing the spread of Dublin between cattle farms requires an understanding of the local pathways for the direct and indirect transmission of bacteria. Identifying key risk factors is complicated due to the numerous pathways through which the bacteria can be introduced and established on dairy cattle farms. This study aimed to provide new knowledge about the effect of biosecurity in dairy farms in Dublin-enzootic areas of Denmark. The association between the researcher-assessed biosecurity level and the risk of introducing and establishing Dublin in farms was investigated by following a monthly recalculated cohort of dairy farms with no test-positive Dublin surveillance results over the previous 2 years. There were 37 new test-positive farms matched by herd size with 74 control farms that remained test negative in the mandatory Dublin surveillance programme. A published Biosecurity Assessment Framework for Dublin (BAF-SD) was used to systematically and semi-quantitatively assess the on-farm biosecurity practices across 12 farm sections. Each section was scored on a scale from 0 (total lack of biosecurity measures) to 100 (excellent biosecurity) based on observations and interviews. Lower biosecurity scores in the sections" entrance area," "pick-up-delivery of calves," "calves < 130 days," "cattle > 130 days," and "storage of feed and feeding" were associated with becoming test-positive for . Dublin at a 90% confidence interval (CI) level in univariable logistic analyses. In the multivariable analysis, a higher weighted biosecurity score across all sections was found to be associated with ( < 0.05) with lower odds of becoming test-positive for Dublin (odds ratio [OR] = 0.64 per 10-unit increase in biosecurity level). None of the study farms had very good (score 80 to <90) or excellent biosecurity (score of 90 or above), highlighting the opportunities for biosecurity improvements on-farm. In conclusion, the current biosecurity levels in Danish farms appear insufficient to resist the infection pressure of Dublin from the farm surroundings. Hence, biosecurity practices need to be improved, and/or the infection pressure needs to be reduced, to lower the number of new test-positive dairy cattle farms in Denmark.
都柏林沙门氏菌（. Dublin）是一种适应牛群的细菌，在许多国家的牛群中呈地方流行性发生。防止都柏林沙门氏菌在奶牛场之间传播需要了解细菌直接和间接传播的当地途径。由于细菌可通过多种途径引入并在奶牛场定殖，因此确定关键风险因素较为复杂。本研究旨在提供有关丹麦都柏林沙门氏菌地方流行区奶牛场生物安全效果的新知识。通过跟踪一组在过去2年中都柏林沙门氏菌监测结果无检测阳性的奶牛场（每月重新计算一次队列），调查了研究人员评估的生物安全水平与农场引入并定殖都柏林沙门氏菌风险之间的关联。有37个新的检测阳性农场，按畜群规模与74个在强制性都柏林沙门氏菌监测计划中仍为检测阴性的对照农场进行匹配。使用已发表的都柏林沙门氏菌生物安全评估框架（BAF-SD）对12个农场区域的农场生物安全措施进行系统和半定量评估。根据观察和访谈，每个区域的评分范围为0（完全没有生物安全措施）至100（优秀的生物安全）。在单变量逻辑分析中，“入口区域”“犊牛接送”“13日龄以下犊牛”“13日龄以上牛”以及“饲料储存和投喂”等区域较低的生物安全得分与都柏林沙门氏菌检测呈阳性相关，置信区间（CI）为90%。在多变量分析中，发现所有区域的加权生物安全得分较高与都柏林沙门氏菌检测呈阳性的几率较低相关（ < 0.05）（生物安全水平每增加10个单位，优势比[OR] = 0.64）。没有一个研究农场具有非常好（得分80至<90）或优秀的生物安全（得分90或以上），这突出了农场生物安全改进的机会。总之，丹麦农场目前的生物安全水平似乎不足以抵御来自农场周边环境的都柏林沙门氏菌感染压力。因此，需要改进生物安全措施，和/或降低感染压力，以减少丹麦新的检测阳性奶牛场数量。
