Wageningen Bioveterinary Research, Lelystad, the Netherlands.
Wageningen Bioveterinary Research, Lelystad, the Netherlands.
Vet Microbiol. 2022 Nov;274:109571. doi: 10.1016/j.vetmic.2022.109571. Epub 2022 Sep 10.
In the veal industry in The Netherlands, each year around 1.2 million "white" veal calves are produced on around 1100 farms. Bovine respiratory disease (BRD) causes serious health issues in these calves, also resulting in high usage of antimicrobials. To reduce antimicrobial usage, a more targeted treatment regime is needed, for which it is necessary to identify the causative agent. This study aimed at determining associations between pathogens and clinical disease, between prevalence of pathogens and BRD outbreaks, and BRD and performance. A cohort study was conducted involving ten veal farms, in which calf respiratory health was evaluated for the first 12 weeks. Whenever there was an outbreak of BRD, as determined by the farm veterinary surgeon, samples were taken from diseased and control calves through broncho-alveolar lavage. From these samples a broad spectrum of micro-organisms were isolated. Performance data were also collected. A total of 23 outbreaks happened during the 12 week study period, mostly in the first six weeks. BRD associated pathogens found were: BHV1, BPI3V, BRSV, BVDV, Pasteurella multocida, Mannheimia haemolytica, Trueperella pyogenes, Histophilus somni, Mycoplasma bovis, Mycoplasma bovirhinis and Mycoplasma dispar. For most BRD associated pathogens, there was no clear association between presence or prevalence of the micro-organisms and clinical issues. Only T. pyogenes (7.4% in healthy, 14.6% in diseased calves, p 0.013), M. bovis (37.6% and 63.2% respectively, p 0.001) and BVDV (9.9% and 16.9% respectively, p 0.03) were found more often in diseased animals. BPI3V was found in a few early outbreaks, which might suggest involvement in early outbreaks. It appears to be difficult to associate specific pathogens to outbreaks at the species level. BRD is the major reason for treatment with antimicrobials. More specific knowledge about the association between pathogens and health/disease could help to reduce antimicrobial use.
在荷兰的小牛肉产业中，每年约有 120 万头“白色”小牛肉犊牛在 1100 多个农场生产。牛呼吸道疾病 (BRD) 会导致这些小牛出现严重的健康问题，同时也导致大量使用抗生素。为了减少抗生素的使用，需要一种更有针对性的治疗方案，这就需要确定病原体。本研究旨在确定病原体与临床疾病之间、病原体与 BRD 爆发之间以及 BRD 与性能之间的关联。进行了一项队列研究，涉及 10 个小牛肉农场，其中评估了小牛呼吸道健康状况，为期 12 周。只要农场兽医确定发生 BRD 爆发，就会通过支气管肺泡灌洗从小牛和对照小牛中采集样本。从这些样本中分离出了广谱微生物。还收集了性能数据。在 12 周的研究期间共发生了 23 次爆发，大多发生在头六周。发现的与 BRD 相关的病原体包括：牛疱疹病毒 1 型、牛副流感病毒 3 型、牛呼吸道合胞体病毒、牛病毒性腹泻病毒、多杀巴斯德菌、溶血曼海姆菌、化脓隐秘杆菌、副流感嗜血杆菌、牛支原体、牛支原体和牛支原体。对于大多数与 BRD 相关的病原体，没有明确的证据表明微生物的存在或流行与临床问题有关。只有化脓隐秘杆菌（健康牛中为 7.4%，患病牛中为 14.6%，p 0.013）、牛支原体（分别为 37.6%和 63.2%，p 0.001）和牛病毒性腹泻病毒（分别为 9.9%和 16.9%，p 0.03）在患病动物中更常见。在少数早期爆发中发现了牛副流感病毒 3 型，这可能表明其参与了早期爆发。在物种水平上，很难将特定的病原体与爆发联系起来。BRD 是使用抗生素治疗的主要原因。更多关于病原体与健康/疾病之间关联的具体知识可以帮助减少抗生素的使用。
