Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia.
PLoS One. 2019 Mar 21;14(3):e0214158. doi: 10.1371/journal.pone.0214158. eCollection 2019.
The use of dual-purpose chickens is a strategy to avoid killing one-day-old male chicks of egg laying lines. Lohmann Dual (LD) is a novel dual-purpose chicken line created by the crossbreeding of layer and broiler lines. However, many of the cardiovascular diseases of broilers are likely to be associated with intensive genetic selection for growth and feed conversion efficiency. This study aimed to compare the macroscopic and microscopic structure of the heart and the aorta of the LD chicken line with that of the broiler chicken line, Ross 308 (Ross) under typical husbandry conditions for meat production. Eighty, one-day-old male chicks of each line were housed for 5 weeks (Ross) and 9 weeks (LD). Six birds of each line were sampled weekly. Heart mass, thickness of ventricular walls, cardiomyocyte size and blood capillary density as well as aortic diameter and thickness, number of elastic lamellae and elastic fiber percentage in the aortic wall were determined. The growth patterns of the heart were the same in the two lines. Although LD chickens had a lower absolute heart mass than that of Ross chickens, the relative heart mass in both lines was similar. The cardiomyocytes of LD chickens were larger than those of Ross's of the same body weight (BW), nevertheless both lines had similar thicknesses of their ventricular walls. The blood capillary density was greater in the LD heart than in that of the Ross heart. The aorta of LD chickens had proportionally; a greater aortic lumen radius, larger numbers of elastic lamellae and more elastic fibers than in Ross chickens. Our results suggest that the heart and aorta of the LD chickens have not been disadvantaged by their intensive genetic selection; furthermore, LD chickens have a better myocardial capillary supply and better aortic mechanical properties than those of Ross chickens.
两用品鸡的使用是避免淘汰蛋鸡系一日龄雄性小鸡的策略。罗曼双宝（LD）是一种新型的两用品鸡系，由蛋鸡系和肉鸡系杂交而成。然而，许多肉鸡的心血管疾病可能与生长和饲料转化率的强化遗传选择有关。本研究旨在比较罗曼双宝（LD）和罗斯 308（Ross）肉鸡系在典型的肉用生产条件下的心脏和主动脉的宏观和微观结构。80 只 1 日龄雄性小鸡被饲养 5 周（Ross）和 9 周（LD）。每条线每周抽取 6 只鸟。测定心脏质量、心室壁厚度、心肌细胞大小和毛细血管密度以及主动脉直径和厚度、主动脉壁中弹性小体的数量和弹性纤维百分比。两条线的心脏生长模式相同。尽管 LD 鸡的绝对心脏质量低于 Ross 鸡，但两条线的相对心脏质量相似。LD 鸡的心肌细胞比 Ross 鸡的心肌细胞大，但体重相同的心室壁厚度相似。LD 心脏的毛细血管密度大于 Ross 心脏。LD 鸡的主动脉比例上；主动脉腔半径较大，弹性小体数量较多，弹性纤维较多。我们的研究结果表明，LD 鸡的心脏和主动脉没有因其强化遗传选择而处于不利地位；此外，LD 鸡的心肌毛细血管供应比 Ross 鸡更好，主动脉的机械性能也更好。
