Li Shilin, Zhao Xiaoyu, Zheng Xu, Chen Hui, Zhou Rongyan, Shi Lei, Liu Huage, Xu Lijun, Ning Zhonghua, Wang Dehe
College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China.
Baoding Xingrui Agriculture and Animal Husbandry Development Co., Ltd. Baoding 071001, China.
Poult Sci. 2025 Jun 27;104(10):105502. doi: 10.1016/j.psj.2025.105502.
To enhance production efficiency, the egg industry increasingly extends the laying cycle of hens. However, this extension exacerbates the decline in egg quality during the late laying period. To improve egg quality throughout the extended laying period of laying hens, this study analyzed 11 egg quality traits: eggshell strength (ESS), eggshell thickness (EST), eggshell weight (ESW), eggshell ratio (ESR), egg weight (EW), yolk weight (YW), yolk ratio (YR), egg shape index (EI), Haugh unit (HU), yolk color (YC), and eggshell membrane thickness (ESMT) in 2,577 White Leghorn hens across 35, 40, 50, 60, 70, 80, 90, and 100 wk of age. Phenotype and genetic parameter variations were systematically evaluated. Results showed that ESS, YC, and ESMT had low heritability (0.05-0.25), while ESW, ESR, EST, EI, and HU exhibited moderate heritability (0.20-0.35). EW, YW, and YR had higher heritability (0.30-0.54). Heritability for EW, ESS, and HU decreased with age, while YW and YR showed increasing trends. Positive phenotypic and genetic correlations were observed among shell-related traits (ESS, ESW, ESR, EST) and between EW and YW. Conversely, YR showed negative correlations with ESW and HU. Cluster analysis grouped shell-related traits (ESR, EST, ESW, ESS) into three phases (35-50 wk, 60-70 wk, 80-100 wk) and egg-weight-related traits (EW, YW, YR) into three phases (35-40 wk, 50-60 wk, 70-90 wk). Egg quality traits were categorized into three classes: shell quality (ESS, ESW, ESR, EST), egg-weight-related traits (EW, YW, YR), and other traits (EI, HU, YC, ESMT). Weight analysis indicated higher weights for egg quality traits at 40-50 wk, suggesting this period may be more representative for selection. Among shell traits, EST had the highest weight (27.01 %), and ESS the lowest (19.85 %), prioritizing EST as a shell quality indicator. This study reveals dynamic patterns of egg quality traits during the 35-100-week laying cycle, providing insights for genetic improvement and trait simplification. These findings offer comprehensive insights into egg quality changes and genetic architecture during extended production cycles.
为提高生产效率，蛋鸡行业越来越多地延长母鸡的产蛋周期。然而，这种延长加剧了产蛋后期鸡蛋品质的下降。为了在延长的产蛋期内提高蛋鸡的鸡蛋品质，本研究分析了2577只白来航蛋鸡在35、40、50、60、70、80、90和100周龄时的11个鸡蛋品质性状：蛋壳强度（ESS）、蛋壳厚度（EST）、蛋壳重量（ESW）、蛋壳比例（ESR）、蛋重（EW）、蛋黄重量（YW）、蛋黄比例（YR）、蛋形指数（EI）、哈夫单位（HU）、蛋黄颜色（YC）和蛋壳膜厚度（ESMT）。系统评估了表型和遗传参数的变化。结果表明，ESS、YC和ESMT的遗传力较低（0.05 - 0.25），而ESW、ESR、EST、EI和HU表现出中等遗传力（0.20 - 0.35）。EW、YW和YR具有较高的遗传力（0.30 - 0.54）。EW、ESS和HU的遗传力随年龄增长而降低，而YW和YR呈上升趋势。在与蛋壳相关的性状（ESS、ESW、ESR、EST）之间以及EW和YW之间观察到正的表型和遗传相关性。相反，YR与ESW和HU呈负相关。聚类分析将与蛋壳相关的性状（ESR、EST、ESW、ESS）分为三个阶段（35 - 50周、60 - 70周、80 - 100周），将与蛋重相关的性状（EW、YW、YR）分为三个阶段（35 - 40周、50 - 60周、70 - 90周）。鸡蛋品质性状分为三类：蛋壳品质（ESS、ESW、ESR、EST）、与蛋重相关的性状（EW、YW、YR）和其他性状（EI、HU、YC、ESMT）。权重分析表明，40 - 50周龄时鸡蛋品质性状的权重较高，表明该时期可能更具选择代表性。在蛋壳性状中，EST的权重最高（27.01%），ESS的权重最低（19.85%），优先将EST作为蛋壳品质指标。本研究揭示了35 - 100周产蛋周期内鸡蛋品质性状的动态模式，为遗传改良和性状简化提供了见解。这些发现为延长生产周期内的鸡蛋品质变化和遗传结构提供了全面的见解。
