Genomic variation exists in cattle that affects their susceptibility to the complex of pathogens responsible for bovine respiratory disease (BRD). Heritability estimates and genome-wide association analyses (GWAA) support the role of host genomic variation in BRD susceptibility. Heritability estimates for BRD susceptibility range from 0.02 to 0.29 depending on the population, the definition of the disease, and the accuracy of diagnosis. GWAA have identified genomic regions (loci) associated with BRD in beef and dairy cattle based on a variety of BRD diagnostic criteria. National standards need to be developed for BRD diagnostics and reporting to facilitate selection. Commercial genotyping is available to predict BRD susceptibility in dairy cattle and for the selection of replacement animals. Disease pathogen profiles vary by region and can result in genetic heterogeneity where different loci are important for susceptibility to different BRD pathogens. Although the identification of the BRD pathogens may not be critical for treatment, it is of paramount importance in identifying loci that render cattle susceptible to the disease. Identification of loci associated with host susceptibility to BRD provides a foundation for genomic selection to reduce disease and opens the possibilities to a better understanding of how the host defends itself.

中文翻译：

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基因组学：宿主的基因型及其与牛呼吸道疾病的相关性

牛中存在基因组变异，这会影响它们对导致牛呼吸道疾病 (BRD) 的病原体复合物的易感性。遗传力估计和全基因组关联分析 (GWAA) 支持宿主基因组变异在 BRD 易感性中的作用。BRD 易感性的遗传力估计值范围为 0.02 至 0.29，具体取决于人群、疾病的定义和诊断的准确性。GWAA 已根据各种 BRD 诊断标准确定了与牛肉和奶牛中 BRD 相关的基因组区域（基因座）。需要为 BRD 诊断和报告制定国家标准，以方便选择。商业基因分型可用于预测奶牛的 BRD 易感性和选择替代动物。疾病病原体谱因地区而异，并可能导致遗传异质性，其中不同的基因座对不同 BRD 病原体的易感性很重要。尽管 BRD 病原体的鉴定对于治疗可能并不重要，但它对于鉴定使牛易患该疾病的基因座至关重要。鉴定与宿主对 BRD 易感性相关的基因座为基因组选择以减少疾病提供了基础，并为更好地了解宿主如何防御自身提供了可能性。