Context Exposure to maternal hormones can permanently alter an embryo’s developmental trajectory. Maternal mediated effects have significant potential in the chicken meat industry, as breeder hens are feed restricted in a bid to improve performance. Evidence suggests breeder hens are chronically stressed, resulting from periods of prolonged hunger. However, evidence linking embryonic exposure to early-life stress and altered offspring phenotype in meat chickens is lacking. Additionally, methods to alleviate the phenotypic consequences of early-life stress have not been comprehensively explored. Nutritional supplementation with amino acids, such as arginine (Arg), may provide one such option, as Arg reportedly enhances performance characteristics in chicken meat birds. Aims An in ovo study was conducted to investigate whether exposure to in ovo stress altered offspring performance in meat chickens. Additionally, Arg was supplemented post-hatch to alleviate reductions in performance, hypothesised to occur as a result of exposure to corticosterone. Method A total of 400 eggs were divided into two groups and administered a corticosterone (CORT) or control (CON) solution at embryonic Day 11. At hatch, birds were separated into four groups based on in ovo and dietary treatments: CORT-Control, CORT-Arg, CON-Arg and CON-Control. Birds fed supplementary Arg diets received an Arg : lysine inclusion of 125%. Bodyweight (bwt) and feed conversion were recorded weekly. Birds were euthanised at embryonic Day 15, Day 0, 7, 21 (n = 40 birds/time point), 28 and 35 (n = 48 birds/time point) for organ collection. A total of 12 additional female birds were euthanised and subjected to a dual-energy X-ray absorptiometry scan for body composition at Day 35. Results Neither in ovo nor diet treatments influenced bwt, bwt gain, feed conversion or plasma corticosterone at any time point, nor did any in ovo by diet interaction exist. Female birds exposed to CORT exhibited significantly greater fat mass (%bwt; P = 0.007) and reduced lean mass (%bwt; P = 0.026) compared with CON females at Day 35. Supplementary Arg did not influence bird body composition. Conclusions These findings suggest in ovo exposure to CORT may negatively influence body composition of female birds. Implications Understanding the effects of the maternal/in ovo environment may provide a novel approach to further improve carcass quality and flock uniformity.

中文翻译：

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在 35 日龄雌性鸡肉禽中，无论是否补充精氨酸，卵内皮质酮给药都会改变身体成分

背景 暴露于母体激素可以永久改变胚胎的发育轨迹。母体介导的影响在鸡肉行业具有巨大的潜力，因为种鸡受到饲料限制以提高性能。有证据表明，由于长期饥饿，种鸡长期处于压力之下。然而，缺乏将胚胎暴露与早期生活压力和肉鸡后代表型改变联系起来的证据。此外，尚未全面探索减轻早期生活压力表型后果的方法。补充氨基酸，如精氨酸 (Arg)，可以提供一种这样的选择，因为据报道，Arg 可增强鸡肉禽类的性能特征。目的 一项卵内研究旨在调查暴露于卵内应激是否会改变肉鸡后代的表现。此外，孵化后补充精氨酸以减轻性能下降，假设是由于暴露于皮质酮而发生的。方法 将总共 400 个鸡蛋分为两组，并在胚胎第 11 天施用皮质酮 (CORT) 或对照 (CON) 溶液。在孵化时，根据卵内和日粮处理将鸟类分为四组：CORT-Control、 CORT-Arg、CON-Arg 和 CON-Control。饲喂补充 Arg 日粮的鸡只接受了 125% 的 Arg: 赖氨酸。每周记录体重 (bwt) 和饲料转化率。在胚胎第 15 天、第 0、7、21 天（n = 40 只鸟/时间点）、28 和 35 天（n = 48 只鸟/时间点）对鸟类实施安乐死以收集器官。在第 35 天，共有 12 只额外的雌性鸟类被安乐死并接受了双能 X 射线吸收仪扫描身体成分。结果 在任​​何时间点，蛋内处理和日粮处理均不影响体重、体重增加、饲料转化率或血浆皮质酮，也不存在任何蛋内饮食相互作用。与第 35 天的 CON 雌鸟相比，暴露于 CORT 的雌鸟表现出显着更大的脂肪量（%bwt；P = 0.007）和减少的瘦体重（%bwt；P = 0.026）。补充 Arg 不影响鸟的身体成分。结论 这些发现表明，蛋内暴露于 CORT 可能会对雌性鸟类的身体成分产生负面影响。意义 了解母体/卵内环境的影响可能为进一步提高胴体质量和鸡群均匀性提供一种新方法。