Epidemiology of mastitis and interactions of environmental factors on udder health in the compost barn system

ABSTRACT This study aimed to describe the epidemiological indexes of mastitis, milk quality and udder hygiene in the Compost Barn system, as well as to search for associations between isolated pathogens from milk with compost characteristics. Three dairy herds participated in the study, and the samples were collected during different periods on each farm. Individual milk samples were collected in duplicate for SCC analysis and microbiological culture. Environmental pathogens caused most cases of clinical mastitis on farm 2, and contagious pathogens caused the most cases on farm 1. Bed moisture was not associated with the incidence of environmental pathogens. Most of the animals remained in good udder hygiene during the study. Poor udder hygiene contributed to the increased incidence of environmental pathogens in one of the farms. A higher number of animals with a hygiene score of ≥ 2 were observed during the warmer and rainfall periods. There was no association between hygiene scores and somatic cell counts. The results suggest that pathogens isolated from milk in animals confined in Compost Barn under tropical climate are like other confinement systems adopted elsewhere. The year period influenced the udder hygiene score, reinforcing the importance of bed management throughout the year.

摘要 本研究旨在阐明堆肥垫料牛舍（Compost Barn）系统中乳腺炎、牛乳品质与乳房卫生的流行病学指标，并探究牛乳分离病原菌与堆肥垫料特性之间的关联。本研究共纳入3个奶牛场，各场均于不同时段采集样本。为开展体细胞计数（Somatic Cell Count, SCC）分析与微生物培养，我们采集了两份平行的个体牛乳样本。2号场的临床乳腺炎病例多由环境病原菌引发，而1号场则以接触性病原菌为主要致病原。垫料湿度与环境病原菌的发病率无显著关联。研究期间，多数奶牛的乳房卫生状况良好。其中一个奶牛场中，乳房卫生不佳会导致环境病原菌发病率升高。在温暖多雨时段，乳房卫生评分≥2分的奶牛数量更多。乳房卫生评分与体细胞计数之间无明显关联。本研究结果表明，热带气候下采用堆肥垫料牛舍饲养的奶牛，其牛乳分离病原菌特征与其他地区所采用的各类圈养系统相似。年度时段会对乳房卫生评分产生影响，这进一步凸显了全年开展垫料管理的重要性。