There is growing interest in using genetic selection to obtain more resilient farm animals (i.e. that are minimally affected by disturbances or rapidly recover from them). The aims of this study were to: (i) estimate the genetic parameters of resilience indicator traits based on egg production data, (ii) assess whether these traits are genetically correlated in purebreds and crossbreds, and (iii) assess the genetic correlations of these traits with egg production (EP) as total number of eggs between 25 and 83 weeks. Purebred hens (33,825 from a White Leghorn (WA) line and 34,397 from a Rhode Island (BD) line were housed in individual cages, while crossbred hens were housed in collective cages of 6 to 8 paternal half-sibs (12,852 WA and 3898 BD crossbred groups, where the name of the group refers to the line used as the sire). Deviations of a hen’s weekly egg production from the average of the corresponding batch were calculated. Resilience indicator traits investigated were the natural logarithm of the variance (LNVAR), the skewness (SKEW), and the lag-one autocorrelation (AUTO-R) of these deviations. In both purebred lines, EP was estimated to be lowly heritable (WA: 0.11 and BD: 0.12). Resilience indicators were also estimated to be lowly heritable in both lines (LNVAR: 0.10 and 0.12, SKEW: 0.04 and 0.02, AUTO-R: 0.06 and 0.08 in WA and BD, respectively). In both crossbred groups, EP, AUTO-R, and SKEW were estimated to be less heritable than in purebreds (EP: $$h^{2}$$ ≤ 0.07; and resilience indicator traits: $$h^{2}$$ ≤ 0.03), while LNVAR had an $$h^{2}$$ estimate that was similar to or higher in crossbreds ( $$h^{2}$$ ranged from 0.13 to 0.21) than in purebreds. In both purebreds and crossbreds, resilience indicator traits were estimated to have favorable genetic correlations with EP and between each other. For all traits and in both lines, estimates of genetic correlations between purebreds and crossbreds ( $$r_{pc}$$ ) differed from 1 and ranged from 0.16 to 0.63. These results show that selection for resilience based on EP data can be considered in breeding programs for layers. Genetic improvement of resilience in crossbreds can be achieved by using information on purebreds, but would be greatly enhanced by the integration of information on crossbreds in breeding programs.

中文翻译：

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利用产蛋量纵向记录研究纯种和杂交蛋鸡恢复力的遗传背景

人们越来越关注使用遗传选择来获得更有弹性的农场动物（即受干扰影响最小或从干扰中快速恢复的动物）。本研究的目的是：（i）根据产蛋数据估计弹性指标性状的遗传参数，（ii）评估这些性状在纯种和杂交种中是否存在遗传相关性，以及（iii）评估这些性状的遗传相关性产蛋量 (EP) 为 25 至 83 周的产蛋总数。纯种母鸡（来自 White Leghorn (WA) 品系的 33,825 只和来自罗德岛 (BD) 品系的 34,397 只被圈养在单独的笼子中，而杂交母鸡被圈养在 6 至 8 只父系半同胞（12,852 WA 和 3898 BD）的集体笼中杂交群体，其中群体的名称是指用作父亲的品系）。计算了母鸡每周产蛋量与相应批次平均值的偏差。调查的弹性指标特征是方差的自然对数 (LNVAR)、偏度 (SKEW) 和这些偏差的滞后一自相关 (AUTO-R)。在两个纯种系中，估计 EP 的遗传性较低（WA：0.11 和 BD：0.12）。复原力指标也被估计在两条线中的遗传性较低（LNVAR：0.10 和 0.12，SKEW：0.04 和 0.02，AUTO-R：在 WA 和 BD 中分别为 0.06 和 0.08）。在两个杂交组中，估计 EP、AUTO-R 和 SKEW 的可遗传性低于纯种（EP：$$h^{2}$$ ≤ 0.07；弹性指标性状：$$h^{2}$ $ ≤ 0.03)，而 LNVAR 的 $$h^{2}$$ 估计值与纯种杂交种相似或更高（$$h^{2}$$ 范围从 0.13 到 0.21）。在纯种和杂交种中，弹性指标性状估计与 EP 以及彼此之间具有良好的遗传相关性。对于所有性状和两个品系，纯种和杂交种之间的遗传相关性估计值 ($$r_{pc}$$ ) 与 1 不同，范围为 0.16 至 0.63。这些结果表明，在蛋鸡的育种计划中可以考虑基于 EP 数据的弹性选择。杂交种恢复力的遗传改进可以通过使用纯种的信息来实现，但是通过将杂交种的信息整合到育种计划中可以大大增强。纯种和杂交种之间遗传相关性的估计值 ($$r_{pc}$$) 与 1 不同，范围为 0.16 至 0.63。这些结果表明，在蛋鸡的育种计划中可以考虑基于 EP 数据的弹性选择。杂交种恢复力的遗传改进可以通过使用纯种的信息来实现，但是通过将杂交种的信息整合到育种计划中可以大大增强。纯种和杂交种之间遗传相关性的估计值 ($$r_{pc}$$) 与 1 不同，范围为 0.16 到 0.63。这些结果表明，在蛋鸡的育种计划中可以考虑基于 EP 数据的弹性选择。杂交种恢复力的遗传改进可以通过使用纯种的信息来实现，但是通过将杂交种的信息整合到育种计划中可以大大增强。