摘要
The accumulation of inbreeding and the loss of genetic diversity is a potential problem in Holstein dairy cattle. The goal of this study was to estimate inbreeding levels and other measures of genetic diversity, using pedigree information from Iranian Holstein cattle. Edited pedigree included 1 048 572 animals. The average number of discrete generation equivalents and pedigree completeness index reached 13.4 and 90%, respectively. The rate of inbreeding was 0.3% per year. Effective number of founders, founder genomes, non-founders and ancestors of animals born between 2003 and 2011 were 503, 15.6, 16.1 and 25.7, respectively. It was proven that the unequal founder contributions as well as bottlenecks and genetic drift were important reasons for the loss of genetic diversity in the population. The top 10 ancestors with the highest marginal genetic contributions to animals born between 2003 and 2011 and with the highest contributions to inbreeding were 48.20% and 63.94%, respectively. Analyses revealed that the most important cause of genetic diversity loss was genetic drift accumulated over non-founder generations, which occurred due to small effective population size. Therefore, it seems that managing selection and mating decisions are controlling future co-ancestry and inbreeding, which would lead to better handling of the effective population size.
摘要译文
近亲繁殖的积累和遗传多样性的丧失是荷斯坦奶牛的潜在问题。这项研究的目的是评估水平的近亲繁殖和遗传多样性等措施，利用来自伊朗荷斯坦牛系谱资料。编辑谱系包含1572动物。离散代现金等价物和血统完整性指数的平均人数达到13.4和90％，分别为。近亲繁殖的速度为每年0.3％。创始人，创始人的基因组，非创始人和2003年至2011年之间出生的动物祖先的有效人数分别为503，15.6，16.1和25.7，分别。它被证明是不平等的创始人的贡献以及瓶颈和遗传漂变是遗传多样性的人口流失的重要原因。排名前10位的祖先与2003年和2011年之间，并与近亲繁殖的最高贡献出生的动物的最高边际贡献的遗传率分别为48.20％和63.94％。分析表明，遗传多样性丧失的最重要的原因是积累了非创始人代，这是由于小有效群体大小发生了遗传漂变。因此，似乎管理选择和配合决定控制未来共同祖先和近亲繁殖，这将导致更好的处理有效群体的大小。
Mohsen Dadar[1,*]; Saeid Ansari Mahyari[1]; Mohammad Rokouei[2] and Mohammd Ali Edriss[1];. Rates of inbreeding and genetic diversity in Iranian Holstein Cattle[J]. Animal Science Journal, 2014,85(10): 888-894