Every Thoroughbred horse alive today is descended from three stallions and a larger selection of mares in 17th- and 18th-century England. Since then, no horses outside this lineage have been permitted to enter the bloodline. That’s a problem.
现今世上的每一匹纯种马，都是17、18世纪英格兰的三匹种马和一群母马的后代。从那时起，任何这一谱系外的马匹都不被允许进入这一血统。这是个问题。
“We analyzed genetic diversity at thousands of genetic markers across the entire genome in more than 10,000 Thoroughbred horses from all of the major breeding regions of the world. This is the largest set of horses that’s been examined in this way to date.”
“我们收集了世界上所有主要繁殖区一万多匹纯种马的整个基因组数据，分析了其中数千个遗传标记的遗传多样性。这是迄今为止用这种方法检测过的最大马群数量。”
Emmeline Hill, professor at University College Dublin and chief scientist, with an ownership stake, at an equine science company called Plusvital.
埃米琳·希尔是都柏林大学的教授，也是Plusvital马科学公司的持股首席科学家。
“And what we found was that there has been a highly significant increase in inbreeding in the population over the last 45 years and probably the greatest increase in inbreeding is seen in the last 10 or 15 years.”
“我们发现，在过去的45年里，近亲繁殖的数量有了极其显著的增长，而在过去的10年或15年里，近亲繁殖可能达到了最快增长。”
Thoroughbred horse production is tightly controlled. Artificial insemination is not permitted, which means that breeding stallions get moved around a lot for meetups with females. These so-called shuttle stallions can mate with hundreds of mares per mating season. And there are two mating seasons: one in the northern hemisphere and the other in the southern.
纯种马的培育受到了严格的控制，不允许进行人工授精，这意味着用于繁殖的种马为了与母马交配会四处奔波。在每个交配季，这些“移动种马”能与数百头母马交配，而一年有两个交配季：北半球一个，南半球还有一个。
“In our study, 97 percent of the horses traced back to a single horse called Northern Dancer, arguably the most successful stallion of the 20th century. And his descendants have been the dominant sire lines in Australia and Europe for the last 25 years.”
“在我们的研究中，97%的马可以追溯到一匹名为‘北方舞者’的马，它可以说是20世纪最成功的种马。在过去的25年里，他的后代一直是澳大利亚和欧洲种马的主要父系。”
Northern Dancer won the Kentucky Derby in 1964.
北方舞者是1964年的肯塔基德比赛马会的冠军。
Breeding pairs are chosen for their athletic prowess and competitive behavior, leading to strong selection for genes related to muscle performance and behavior ...
配种对象的选择依据的是它们的运动能力和竞争行为，因此是一种对与肌肉性能和行为相关基因的强筛选。
“Traits that all have to come together in the optimal fashion to produce an elite athlete.”
“为了培育出一名运动精英，所有这些特质必须以最佳方式结合在一起。”
But without genetic diversity, you can get health and behavior issues related to inbreeding.
但失去了遗传多样性，就可能会遇到与近亲繁殖相关的健康和行为问题。
“The Thoroughbred is unusual in that most managed animal and even plant-production systems have genetic monitoring in place. But the Thoroughbred has no genomic selection or population management that is addressed at an industry-wide level.”
“纯种马的不寻常之处在于，人类管理的大部分动物甚至植物的繁育系统都有遗传监测，但纯种马则没有整个行业层面的全基因组选择或马群管理。”
The study by Hill and hercolleagues is in the journal Scientific Reports. [Beatrice A. McGivney et al., Genomic inbreeding trends, influential sire lines and selectionin the global Thoroughbred horse population]
希尔同事的这项研究发表在《科学报告》杂志上。
Hill’s genetic testing system is available through her company.
你可以通过希尔的公司获取她的基因测试系统。
“With the DNA of a mare and the DNA of a stallion, we can make in silico predictions about the likely level of inbreeding in the hypothetical foal that might arise from that mating.”
“有了母马和种马的DNA，我们就可以用生物信息学来预测配种繁育的小马驹可能的近亲繁殖程度。”
Every Thoroughbred horse alive today is descended from three stallions and a larger selection of mares in 17th- and 18th-century England. Since then, no horses outside this lineage have been permitted to enter the bloodline. That’s a problem.
“We analyzed genetic diversity at thousands of genetic markers across the entire genome in more than 10,000 Thoroughbred horses from all of the major breeding regions of the world. This is the largest set of horses that’s been examined in this way to date.”
Emmeline Hill, professor at University College Dublin and chief scientist, with an ownership stake, at an equine science company called Plusvital.
“And what we found was that there has been a highly significant increase in inbreeding in the population over the last 45 years and probably the greatest increase in inbreeding is seen in the last 10 or 15 years.”
Thoroughbred horse production is tightly controlled. Artificial insemination is not permitted, which means that breeding stallions get moved around a lot for meetups with females. These so-called shuttle stallions can mate with hundreds of mares per mating season. And there are two mating seasons: one in the northern hemisphere and the other in the southern.
“In our study, 97 percent of the horses traced back to a single horse called Northern Dancer, arguably the most successful stallion of the 20th century. And his descendants have been the dominant sire lines in Australia and Europe for the last 25 years.”
Northern Dancer won the Kentucky Derby in 1964.
Breeding pairs are chosen for their athletic prowess and competitive behavior, leading to strong selection for genes related to muscle performance and behavior ...
“Traits that all have to come together in the optimal fashion to produce an elite athlete.”
But without genetic diversity, you can get health and behavior issues related to inbreeding.
“The Thoroughbred is unusual in that most managed animal and even plant-production systems have genetic monitoring in place. But the Thoroughbred has no genomic selection or population management that is addressed at an industry-wide level.”
The study by Hill and hercolleagues is in the journal Scientific Reports. [Beatrice A. McGivney et al., Genomic inbreeding trends, influential sire lines and selectionin the global Thoroughbred horse population]
Hill’s genetic testing system is available through her company.
“With the DNA of a mare and the DNA of a stallion, we can make in silico predictions about the likely level of inbreeding in the hypothetical foal that might arise from that mating.”
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