Aviagen Ltd., Newbridge, Midlothian EH28 8SZ, UK.
Poult Sci. 2012 Dec;91(12):3032-43. doi: 10.3382/ps.2012-02578.
Leg health is an important component of broiler welfare and the economics of broiler production. This study presents the development of leg health in 3 purebred commercial broiler lines during 25 yr of selection and investigates the genetic background of leg health traits in current populations of these lines. The leg health traits were deformities of the long bones (LD) and crooked toes (CT), recorded since 1985, and tibial dyschondroplasia (TD) and hock burn (HB), recorded since 1990. The prevalence of CT and HB decreased mainly in the first decade (range among lines -1.2 to -2.3% and -1.3 to -1.5% per year, respectively), after which it stabilized at low levels. The prevalence of LD and TD decreased by -0.6 to -0.9% and -0.4 to -1.2% per year, respectively. Genetic parameters were estimated using data from 4 recent generations. The BW ranged from 2.0 to 2.4 kg at 5 wk of age; the prevalences of LD, CT, TD, and HB from 8.6 to 12.9%, 0.6 to 2.6%, 4.6 to 8.0%, and 4.0 to 12.2%, respectively. Estimates of heritability were 0.04 to 0.07 for LD, 0.01 to 0.10 for CT, 0.10 to 0.27 for TD, and 0.06 to 0.09 for HB (all SE ≤0.01). Estimates of the genetic correlations between LD and CT were 0.11 to 0.43 (all SE ≤0.09), between these traits and HB were negligible, and of TD with LD, CT, and HB were -0.26 to 0.16 (all SE ≤0.11). Estimates of genetic correlations between the leg health traits and BW were lowly to moderately unfavorable, ranging from 0.09 to 0.37 (all SE ≤0.06). The differences between the lines suggest that strategies for simultaneous improvement of all traits tailored for each line individually have been effective. This research demonstrates the long-term effectiveness of selection for improving leg health in broilers and highlights that, despite somewhat unfavorable genetic correlations with BW, these traits can be improved simultaneously in a balanced breeding program.
腿部健康是肉鸡福利和经济效益的重要组成部分。本研究介绍了在 25 年的选择过程中，3 个纯商业肉鸡系的腿部健康状况的发展，并研究了当前这些系中腿部健康特征的遗传背景。自 1985 年以来，记录了腿部畸形（LD）和脚趾弯曲（CT），自 1990 年以来，记录了胫骨软骨发育不良（TD）和跗关节烧伤（HB）。CT 和 HB 的患病率主要在前十年下降（范围在各系中为每年-1.2 至-2.3%和-1.3 至-1.5%），之后稳定在低水平。LD 和 TD 的患病率分别以每年-0.6 至-0.9%和-0.4 至-1.2%的速度下降。使用最近 4 代的数据估计了遗传参数。BW 在 5 周龄时为 2.0 至 2.4 公斤；LD、CT、TD 和 HB 的患病率分别为 8.6%至 12.9%、0.6%至 2.6%、4.6%至 8.0%和 4.0%至 12.2%。LD 的遗传力估计值为 0.04 至 0.07，CT 为 0.01 至 0.10，TD 为 0.10 至 0.27，HB 为 0.06 至 0.09（所有 SE ≤0.01）。LD 和 CT 之间的遗传相关性估计值为 0.11 至 0.43（所有 SE ≤0.09），这些性状与 HB 的相关性可以忽略不计，TD 与 LD、CT 和 HB 的相关性分别为-0.26 至 0.16（所有 SE ≤0.11）。腿部健康性状与 BW 的遗传相关性从低度到中度不利，范围为 0.09 至 0.37（所有 SE ≤0.06）。系之间的差异表明，针对每个系单独量身定制的同时改善所有性状的策略是有效的。本研究证明了选择对改善肉鸡腿部健康的长期有效性，并强调尽管与 BW 的遗传相关性略不利，但这些性状可以在平衡的繁殖计划中同时得到改善。
