New South Wales Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, New South Wales, Australia.
Dairy UP, The University of Sydney, Camden, New South Wales, Australia.
Aust Vet J. 2024 Jan-Feb;102(1-2):11-18. doi: 10.1111/avj.13293. Epub 2023 Oct 9.
Infectious viral diseases in dairy cattle have substantial implications for milk production, quality and overall animal health. Diagnostic tools providing reliable results are crucial for effective disease control at the farm and industry level. Pooled or bulk tank milk (BTM) can be used as a cost-effective aggregate sample to assess herd disease status in dairy farms.
Detection of pathogens or specific antibodies in milk can be used for monitoring endemic diseases within-farm, region or country-level disease surveillance and to make informed decisions on farm management. The suitability of assays applied to pooled milk samples relies on validation data of fit-for-purpose tests to design an optimal testing strategy. Diverse approaches and variable scope of studies determining test accuracy need to be critically appraised before sourcing the parameters to design sampling strategies and interpreting surveys. Determining if BTM or pooled milk is the best approach for a disease management programme should carefully consider several aspects that will impact the accuracy and interpretation, for example, the size of the lactating herd, the risk of infection in the lactating and non-lactating groups, the expected within-herd prevalence, the duration of infection, the duration and concentration of antibodies in milk and use of vaccination.
There are examples of tests on BTM samples providing efficient assessments of the herd disease status and supporting disease control programmes for viral diseases. However, challenges arise in pooled milk testing due to the need for accurate estimates of the imperfect sensitivity and specificity of the assays. Integration of new biotechnologies could enhance multiplexing and data interpretation for comprehensive surveillance. The development of highly sensitive assays is necessary to meet the demands of larger dairy herds and improve disease detection and assessment.
奶牛传染性病毒病对牛奶生产、质量和动物整体健康有重大影响。提供可靠结果的诊断工具对于在农场和行业层面有效控制疾病至关重要。混合或批量奶（BTM）可作为一种具有成本效益的综合样本，用于评估奶牛场的畜群疾病状况。
在农场内、地区或国家层面监测地方性疾病、进行疾病监测以及就农场管理做出明智决策，可以使用检测奶中病原体或特定抗体的方法。应用于混合奶样的检测方法的适用性依赖于针对特定用途的检验方法的验证数据，以设计最佳的检测策略。在确定采样策略的参数和解释调查结果之前，需要对不同的方法和不同范围的确定检测准确性的研究进行严格评估。确定 BTM 或混合奶是否是疾病管理计划的最佳方法时，需要仔细考虑几个方面，这些方面将影响准确性和解释，例如，泌乳牛群的规模、泌乳和非泌乳牛群的感染风险、预期的畜群内流行率、感染持续时间、奶中抗体的持续时间和浓度以及疫苗接种的使用。
有一些关于 BTM 样本的检测方法的例子，这些方法可以有效地评估畜群的疾病状况，并支持病毒病的疾病控制计划。然而，混合奶检测存在挑战，因为需要准确估计检测方法的不完美敏感性和特异性。新技术的整合可以增强多重检测和数据解释，以进行全面监测。需要开发高度敏感的检测方法，以满足更大的奶牛群的需求，并提高疾病的检测和评估能力。
