Importation of foreign genetics is a widely used genetic improvement strategy. However, even if the foreign genetic merit is currently greater than the domestic genetic merit, differences in foreign and domestic trends mean that the long-term competitiveness of an importation strategy cannot be guaranteed. Gene flow models are used to quantify the impact that a specific subpopulation, such as foreign genetics, can have over time on the genetic or economic benefit of a domestic industry. We used a deterministic recursive gene flow model to predict the commercial performance of lambs born across various subpopulations. Numerous breeding strategies were evaluated by varying market share, proportions of rams selected for mating, genetic trend, superiority of foreign genetics over domestic genetics and frequency of importation. Specifically, an Ireland-New Zealand case study was simulated to quantify the potential gain that could be made by using foreign sire contributions (New Zealand) in a domestic sheep industry (Ireland). Genetic and economic gains were generated from alternative breeding strategies. The ‘base scenario’ (i.e. representing the current industry) predicted an average genetic merit value of €2.51 for lambs born and an annualised cumulative benefit of €45 million (m) after 20 years. Maximum genetic (€9.45 for lambs born) and economic (annualised cumulative benefit of €180 m after 20 years) benefits were achieved by implementing the ‘PRO-intense-market scenario’ which involved shifting market share away from conservative domestic breeders and reducing the proportion of rams that were selected for mating by progressive domestic breeders from the top 40% to the top 20%, without the use of any foreign genetics. The ‘PROFOR scenario’, which considered the use of foreign and progressive domestic genetics, predicted an average genetic merit value of €7.37 for lambs born and an annualised cumulative benefit of €144 m, after 20 years. Our results demonstrate that there is opportunity for a domestic industry to increase industry benefits without the use of foreign genetics but through an attempt to shift the market share away from conservative domestic breeders towards progressive domestic breeders. However, the importation and use of progressive foreign genetics may be an effective method to trigger a change in behaviour of conservative domestic breeders towards the use of progressive genetics.

中文翻译：

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外国公牛对国内绵羊产业的遗传和经济利益；包括爱尔兰-新西兰案例研究

引进外国遗传学是一种广泛使用的遗传改良策略。但是，即使目前国外的遗传优势大于国内的遗传优势，国外趋势和国内趋势的差异也意味着不能保证进口策略的长期竞争力。基因流模型用于量化特定子种群（例如外国遗传资源）随着时间的推移可能对国内产业的遗传或经济利益产生的影响。我们使用确定性递归基因流模型来预测各种亚群之间出生的羔羊的商业表现。通过不同的市场份额，选择用于交配的公羊比例，遗传趋势，外国遗传学优于国内遗传学和进口频率来评估众多育种策略。特别，模拟了爱尔兰-新西兰的案例研究，以量化在国内绵羊产业（爱尔兰）中使用外国公牛贡献（新西兰）可以带来的潜在收益。遗传和经济收益来自替代育种策略。“基本情景”（即代表当前行业）预测，出生的羔羊的平均遗传价值为2.51欧元，20年后的年化累积收益为4500万欧元。通过实施“亲-集市方案”，实现最大的遗传（产羔羊收入9.45欧元）和经济（20年后的年均累积收益为1.8亿欧元）收益，这涉及将市场份额从保守的国内育种者转移出去并减少由国内先进育种者选择交配的公羊的比例从前40％到前20％，不使用任何外国遗传学 “ PROFOR情景”考虑了外国和渐进式国内遗传基因的使用，预测出生20年后的羔羊的平均遗传价值为7.37欧元，年累计收益为1.44亿欧元。我们的结果表明，国内产业有机会在不使用外国遗传资源的情况下，而是通过试图将市场份额从保守的国内育种者转变为进步的国内育种者，来增加产业利益。但是，输入和使用渐进性外来遗传基因可能是触发保守的国内育种者朝着使用渐进性遗传学改变行为的有效方法。该组织考虑了外国和国内先进遗传学的使用，预计出生20年后的羔羊的平均遗传价值为7.37欧元，年累计收益为1.44亿欧元。我们的结果表明，国内产业有机会在不使用外国遗传资源的情况下，而是通过试图将市场份额从保守的国内育种者转变为进步的国内育种者，来增加产业利益。但是，输入和使用渐进性外来遗传基因可能是触发保守的国内育种者朝着使用渐进性遗传学改变行为的有效方法。该组织考虑了外国和国内先进遗传学的使用，预计出生20年后的羔羊的平均遗传价值为7.37欧元，年累计收益为1.44亿欧元。我们的结果表明，国内产业有机会在不使用外国遗传资源的情况下，而是通过试图将市场份额从保守的国内育种者转变为进步的国内育种者，来增加产业利益。但是，输入和使用渐进性外来遗传基因可能是触发保守的国内育种者朝着使用渐进性遗传学改变行为的有效方法。我们的结果表明，国内产业有机会在不使用外国遗传资源的情况下，而是通过试图将市场份额从保守的国内育种者转变为进步的国内育种者，来增加产业利益。但是，输入和使用渐进性外来遗传基因可能是触发保守的国内育种者朝着使用渐进性遗传学改变行为的有效方法。我们的结果表明，国内产业有机会在不使用外国遗传资源的情况下，而是通过试图将市场份额从保守的国内育种者转变为进步的国内育种者，来增加产业利益。但是，输入和使用渐进性外来遗传基因可能是触发保守的国内育种者朝着使用渐进性遗传学改变行为的有效方法。