Abstract There has been a significant decrease in genetic diversity on a global scale for several livestock species, including beef cattle. Therefore, the aim of this study was to deliver fine-scale analysis of the genomic structure and to describe the diversity status of six beef cattle breeds, with a specific focus on genomic inbreeding and the trend of effective population size. The genome-wide data of 639 animals belonging to cosmopolitan (Aberdeen Angus, Charolais, Hereford and Limousin) and local (Piedmontese and Romagnola) cattle breeds were included due to their importance for the local and global beef industry in Europe. In addition, the local dual-purpose Slovak Pinzgau was used to extend the study due to increasing interest from beef cattle breeders in Slovakia. The results showed that more than 3% of the Aberdeen Angus, Hereford and Romagnola genomes, less than 1% of the Limousin, Charolais and Slovak Pinzgau genomes and 0.38% of the Piedmontese genome could have been significantly affected by the mating of relatives over the last three generations. The estimates of effective population size indicated a linear decline within each of the analysed populations. The decrease was mainly evident in populations of the Slovak Pinzgau (7.39 animals per generation), Limousin, Piedmontese and Charolais cattle (average 5 animals per generation). Due to the fact that the decrease in effective population size may be accompanied by a decrease in breed competitiveness with regard to a changing production environment, genetic diversity should be continuously monitored to preserve the long-term potential of the analysed breeds. Highlights Decreased diversity across beef breeds is evident Monitoring genetic diversity is needed to prevent inbreeding depression Use of genomic data can increase the accuracy of breeding schemes

中文翻译：

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六个肉牛品种的精细分析揭示了它们的基因组多样性模式

摘要 在全球范围内，包括肉牛在内的几种牲畜物种的遗传多样性显着下降。因此，本研究的目的是对基因组结构进行精细分析，并描述六个肉牛品种的多样性状况，特别关注基因组近亲繁殖和有效种群规模的趋势。由于它们对欧洲当地和全球牛肉产业的重要性，包括属于世界性（阿伯丁安格斯、夏洛来、赫里福德和利穆赞）和当地（皮埃蒙特和罗马涅）牛品种的 639 只动物的全基因组数据。此外，由于斯洛伐克肉牛饲养者的兴趣增加，当地的两用斯洛伐克 Pinzgau 被用于扩展研究。结果显示，超过 3% 的 Aberdeen Angus，Hereford 和 Romagnola 基因组、不到 1% 的 Limousin、Charolais 和 Slovak Pinzgau 基因组以及 0.38% 的 Piedmontese 基因组可能受到过去三代亲属交配的显着影响。有效种群大小的估计表明每个分析种群内的线性下降。减少的主要是斯洛伐克 Pinzgau（每代 7.39 头）、利穆赞、皮埃蒙特和夏洛莱牛（平均每代 5 头）。由于有效种群规模的减少可能伴随着品种在不断变化的生产环境中竞争力的下降，因此应持续监测遗传多样性以保持所分析品种的长期潜力。