Aims We examine the average performance of Border Leicester (BL) flocks that are part of LAMBPLAN, Australia’s sheep performance recording and genetic evaluation system. We also summarise outcomes from the New South Wales Department of Primary Industry’s research on BL improvement, and discuss the performance required for the BL to continue to be a pivotal part of the Australian prime lamb industry. Key results Modest gains have been recorded in the BL in growth since 2000 and faecal egg counts have reduced, suggesting improved worm resistance. The net reproductive rate has slightly improved, while inbreeding continues to increase. In work conducted by the New South Wales Department of Primary Industries, an improved BL flock, encompassing selection for multiple births and a broadening of the breed’s genetic base, had advantages over purebred BLs in many aspects of performance, including a 19.3% advantage in the net reproductive rate. Advantages in fertility were ~5%, litter size ~7% and lamb rearing ability ~5%. BL improved × Merino and (BL improved × BL) × Merino crossbred ewes also had advantages over traditional BL × Merino ewes in their joining performance when joined to Dorset rams. Conclusions Selection in the BL needs to emphasise traits in a manner consistent with their importance to commercial lamb production. Implications Embracing this selection and broadening the BL’s genetic base will assist the BL to maintain its place in the Australian lamb industry.

中文翻译：

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边境莱斯特在澳大利亚的表现

目标 我们检查了作为澳大利亚绵羊性能记录和遗传评估系统 LAMBPLAN 一部分的边境莱斯特 (BL) 羊群的平均性能。我们还总结了新南威尔士州初级产业部关于 BL 改进的研究结果，并讨论了 BL 继续成为澳大利亚优质羊肉产业的关键部分所需的性能。主要结果 自 2000 年以来，BL 的生长取得了适度增长，粪便中的虫卵数量有所减少，表明蠕虫抗性有所提高。净繁殖率略有提高，近亲繁殖继续增加。在新南威尔士州初级产业部开展的工作中，改进了 BL 鸡群，包括多胎选择和扩大该品种的遗传基础，与纯种 BL 相比，在性能的许多方面都具有优势，包括在净繁殖率方面具有 19.3% 的优势。繁殖力的优势是~5%、窝产仔数~7%和羔羊饲养能力~5%。BL改良型×美利奴羊和（BL改良型×BL）×美利奴杂交母羊在与多塞特公羊连接时的接合性能也优于传统的BL×美利奴母羊。结论 BL 中的选择需要以与其对商业羊肉生产的重要性相一致的方式强调性状。意义 接受这种选择并扩大 BL 的遗传基础将有助于 BL 保持其在澳大利亚羊肉产业中的地位。BL改良型×美利奴羊和（BL改良型×BL）×美利奴杂交母羊在与多塞特公羊连接时的接合性能也优于传统的BL×美利奴母羊。结论 BL 中的选择需要以与其对商业羊肉生产的重要性相一致的方式强调性状。意义 接受这种选择并扩大 BL 的遗传基础将有助于 BL 保持其在澳大利亚羊肉产业中的地位。BL改良型×美利奴羊和（BL改良型×BL）×美利奴杂交母羊在与多塞特公羊连接时的接合性能也优于传统的BL×美利奴母羊。结论 BL 中的选择需要以与其对商业羊肉生产的重要性相一致的方式强调性状。意义 接受这种选择并扩大 BL 的遗传基础将有助于 BL 保持其在澳大利亚羊肉产业中的地位。