Local cattle breeds need special attention, as they are valuable reservoirs of genetic diversity. Appropriate breeding decisions and adequate genomic management of numerically smaller populations are required for their conservation. At this point, the analysis of dense genome-wide marker arrays provides encompassing insights into the genomic constitution of livestock populations. We have analyzed the genetic characterization of ten cattle breeds originating from Germany, The Netherlands and Denmark belonging to the group of red dairy breeds in Northern Europe. The results are intended to provide initial evidence on whether joint genomic breeding strategies of these populations will be successful. Traditional Danish Red and Groningen White-Headed were the most genetically differentiated breeds and their populations showed the highest levels of inbreeding. In contrast, close genetic relationships and shared ancestry were observed for the populations of German Red and White Dual-Purpose, Dutch Meuse-Rhine-Yssel, and Dutch Deep Red breeds, reflecting their common histories. A considerable amount of gene flow from Red Holstein to German Angler and to German Red and White Dual-Purpose was revealed, which is consistent with frequent crossbreeding to improve productivity of these local breeds. In Red Holstein, marked genomic signatures of selection were reported on chromosome 18, suggesting directed selection for important breeding goal traits. Furthermore, tests for signatures of selection between Red Holstein, Red and White Dual-Purpose, and Meuse-Rhine-Yssel uncovered signals for all investigated pairs of populations. The corresponding genomic regions, which were putatively under different selection pressures, harboured various genes which are associated with traits such as milk and beef production, mastitis and female fertility. This study provides comprehensive knowledge on the genetic constitution and genomic connectedness of divergent red cattle populations in Northern Europe. The results will help to design and optimize breeding strategies. A joint genomic evaluation including some of the breeds studied here seems feasible.

中文翻译：

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评估北欧红牛种群的遗传背景和基因组相关性

当地的牛品种是需要特别注意的，因为它们是遗传多样性的宝贵资源。为了保护它们，需要对数量较小的种群进行适当的育种决策和适当的基因组管理。在这一点上，密集的全基因组标记阵列的分析提供了对牲畜种群的基因组构成的全面见解。我们分析了来自德国，荷兰和丹麦的十个牛品种的遗传特征，它们属于北欧红色奶牛品种。该结果旨在为这些人群的联合基因组育种策略是否成功提供初步证据。传统的丹麦红和格罗宁根白头犬是遗传分化最强的品种，其种群的近交水平最高。相比之下，德国红和白双重目的，荷兰默兹-莱茵-伊塞尔和荷兰深红品种的种群观察到紧密的遗传关系和共同的血统，反映了它们的共同历史。从红色荷斯坦牛到德国垂钓者，再到德国红白两用的大量基因流被揭示出来，这与频繁的杂交提高了这些地方品种的生产力是一致的。在红色荷斯坦（Red Holstein），第18号染色体上报告了明显的选择基因组特征，表明对重要育种目标性状的定向选择。此外，还测试了红色荷斯坦牛，红色和白色双重目的，和Meuse-Rhine-Yssel发现了所有调查的成对种群的信号。假定处于不同选择压力下的相应基因组区域具有各种基因，这些基因与诸如牛奶和牛肉产量，乳腺炎和女性生育力等性状相关。这项研究为北欧不同红牛种群的遗传组成和基因组联系提供了全面的知识。结果将有助于设计和优化育种策略。联合基因组评估，包括此处研究的某些品种，似乎是可行的。含有与性状相关的各种基因，例如牛奶和牛肉的产量，乳腺炎和女性生育力。这项研究为北欧不同红牛种群的遗传组成和基因组联系提供了全面的知识。结果将有助于设计和优化育种策略。联合基因组评估，包括此处研究的某些品种，似乎是可行的。含有与性状相关的各种基因，例如牛奶和牛肉的产量，乳腺炎和女性生育力。这项研究为北欧不同红牛种群的遗传组成和基因组联系提供了全面的知识。结果将有助于设计和优化育种策略。联合基因组评估，包括此处研究的某些品种，似乎是可行的。