The objective of this study was to estimate Canadian national milk quality parameters and estimate the bulk tank milk (BTM) prevalence of 4 mastitis pathogens, Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma bovis, and Prototheca spp., on Canadian dairy farms. A questionnaire was sent to all Canadian dairy producers. Of the 1,062 producers who completed the questionnaire, 374 producers from across the country were visited and milking hygiene was assessed. Farm-level milk quality data for all Canadian dairy producers was collected from the provincial marketing boards and combined with the questionnaire and farm visit data. In addition, a BTM sample was collected either during the farm visit or by the marketing board in November of 2015 and was tested for 4 major mastitis pathogens using the PathoProof Mastitis Major 4 PCR Assay (Thermo Fisher Scientific Inc., Waltham, MA). Apparent herd-level prevalence was 46% for S. aureus, 6% for Prototheca spp., 0% for M. bovis, and 0% for Strep. agalactiae. Due to the low prevalence of M. bovis and Strep. agalactiae and a lack of significant factors associated with farms testing positive for Prototheca spp., an association analysis could only be carried out for Staph. aureus-positive farms. Factors associated with Staph. aureus-positive farms were not fore-stripping cows before milking (odds ratio = 1.87), milking with a pipeline system (odds ratio = 2.21), and stall bases made of a rubberized surface (mats and mattresses), whereas protective factors were using blanket dry cow therapy (odds ratio = 0.49) and applying a tag or visible mark on cows known to have chronic mastitis infections (odds ratio = 0.45). The Canadian national production-weighted geometric mean somatic cell count was determined to be 208,000 cells/mL. This is the first national dairy study conducted in Canada. Participating farms had higher milk yield; were more likely to have a loose housing system, parlor, or automated milking system; and had lower weighted mean BTM somatic cell count than the national level. Sampling larger farms with better milk quality means the apparent prevalence of the 4 mastitis pathogens likely underestimates the true levels.

这项研究的目的是估计加拿大国家牛奶质量参数，并估计4种乳腺炎病原体，金黄色葡萄球菌，无乳链球菌，牛支原体和原球菌的大罐牛奶（BTM）患病率。spp。，在加拿大的奶牛场上。向所有加拿大乳制品生产商发送了调查表。在完成调查表的1062家生产商中，访问了来自全国的374家生产商并评估了挤奶卫生状况。从省级营销委员会收集了所有加拿大乳制品生产商的农场级牛奶质量数据，并将其与问卷调查和农场访问数据结合在一起。此外，2015年11月在农场访问期间或市场委员会收集了BTM样本，并使用PathoProof乳腺炎4型主要PCR检测试剂盒（Thermo Fisher Scientific Inc.，马萨诸塞州沃尔瑟姆）对4种主要乳腺炎病原体进行了测试。金黄色葡萄球菌的表观畜群患病率为46％，Prototheca spp。为6％，牛分枝杆菌为0％，而牛肝菌为0％。链球菌。无乳。由于牛分枝杆菌和链球菌的患病率较低。无乳杆菌和缺乏与Prototheca spp。呈阳性的农场相关的重要因素，只能对葡萄球菌进行关联分析。金黄色葡萄球菌阳性农场。与葡萄球菌病相关的因素。金黄色阳性农场没有在挤奶前挤奶（赔率= 1.87），在管道系统挤奶（赔率= 2.21）和由橡胶表面制成的摊档底座（垫子和床垫），​​而保护因素则使用毯子干奶疗法（比值= 0.49），并在已知患有慢性乳腺炎感染（比值= 0.45）的母牛身上加上标签或可见标记。确定的加拿大国家生产加权几何平均体细胞计数为208,000个细胞/ mL。这是加拿大进行的第一项全国乳制品研究。参与农场的牛奶产量较高；更有可能拥有宽松的住房系统，客厅或自动挤奶系统；并且其加权平均BTM体细胞计数低于全国水平。