SUMMARY The genetic selection of broilers over the past 60 years has focused narrowly and intensely on production traits, namely growth rate and feed efficiency. This has led to significant welfare problems in birds grown for meat, including leg disorders, cardiovascular diseases, and resulting high mortality rates, while the breeder birds are subjected to severe feed restriction. Bone problems such as bacterial chondronecrosis and tibia dyschondroplasia are prevalent, and recent studies have reported the prevalence of birds with moderate to severe gait impairment to be between 5.5 and 48.8%. Worldwide, over 66 billion broilers are slaughtered annually. This huge scale of meat chicken production means that welfare problems are widespread and are likely to increase in severity due to the increasing global human population, increasing demand for meat, and a continued focus on efficiency of production in the agricultural sector. The commercial broiler industry therefore represents some of the most serious animal welfare issues in agriculture. There is an urgent need to address these problems by making welfare traits high priorities in breeding programmes and integrating these with other breeding goals. Many studies recommend the use of slower-growing breeds that do not have the same welfare problems. Addressing these welfare issues is essential to improve bird welfare and for social acceptability and sustainability of the broiler industry worldwide.

中文翻译：

---

肉鸡的遗传选择和福利后果：综述

总结 在过去的 60 年中，肉鸡的遗传选择一直狭隘而强烈地关注生产性状，即生长速度和饲料效率。这导致肉鸡出现严重的福利问题，包括腿部疾病、心血管疾病和由此产生的高死亡率，而种鸡则受到严格的饲料限制。细菌性软骨坏死和胫骨软骨发育不良等骨骼问题很普遍，最近的研究报告称，中度至重度步态障碍的鸟类患病率在 5.5% 至 48.8% 之间。在全球范围内，每年有超过 660 亿只肉鸡被屠宰。如此庞大的肉鸡生产规模意味着福利问题普遍存在，并且由于全球人口的增加，问题的严重程度可能会增加，对肉类的需求不断增加，并继续关注农业部门的生产效率。因此，商业肉鸡行业代表了农业中一些最严重的动物福利问题。迫切需要通过在育种计划中优先考虑福利性状并将其与其他育种目标相结合来解决这些问题。许多研究建议使用没有相同福利问题的生长较慢的品种。解决这些福利问题对于改善鸟类福利以及全球肉鸡行业的社会可接受性和可持续性至关重要。迫切需要通过在育种计划中优先考虑福利性状并将其与其他育种目标相结合来解决这些问题。许多研究建议使用没有相同福利问题的生长较慢的品种。解决这些福利问题对于改善鸟类福利以及全球肉鸡行业的社会可接受性和可持续性至关重要。迫切需要通过在育种计划中优先考虑福利性状并将其与其他育种目标相结合来解决这些问题。许多研究建议使用没有相同福利问题的生长较慢的品种。解决这些福利问题对于改善鸟类福利以及全球肉鸡行业的社会可接受性和可持续性至关重要。