Department of Animal and Food Sciences, University of Delaware, Newark 19716, USA.
Poult Sci. 2009 Dec;88(12):2610-9. doi: 10.3382/ps.2009-00055.
Selecting chicken for improved meat production has altered the relative growth of organs in modern broiler lines compared with heritage lines. In this study, we compared the growth and feed efficiency of a heritage line, UIUC, with a modern production line, Ross 708, for 5 wk posthatch. During this period, the BW and feed efficiency of the modern strain was higher than that of the heritage line, indicating that the Ross 708 birds were more efficient than the UIUC birds at converting feed to body mass. The relative growth of the breast, heart, liver, and intestine were also compared during these 5 wk. The breast muscle of the heritage line constituted 9% of the total body mass at 5 wk, whereas in the modern line, the breast muscle was 18% of the total mass of the bird. In contrast, the relative size of the heart decreased after d 14 in the modern line, suggesting that selection for increased breast muscle has translated into relatively less weight of the heart muscle. The liver matured earlier in modern lines, possibly improving nutrient utilization as the birds shift from lipid- to carbohydrate-rich feed. Finally, jejunal and ileal sections of the intestine were 20% longer in the modern line, perhaps allowing for increased nutrient absorption.
选择鸡肉以提高肉产量，这改变了现代肉鸡品系与传统品系相比相对器官生长的情况。在这项研究中，我们比较了一个传统品系（UIUC）和一个现代生产品系（罗斯 708）在孵化后 5 周的生长和饲料效率。在此期间，现代品系的 BW 和饲料效率高于传统品系，这表明罗斯 708 鸟比 UIUC 鸟更有效地将饲料转化为体质量。在这 5 周内，还比较了胸、心、肝和肠的相对生长。在 5 周龄时，传统系的胸肌占总体重的 9%，而在现代系中，胸肌占鸟体重的 18%。相比之下，现代系的心脏相对大小在第 14 天之后下降，这表明选择增加胸肌已经转化为相对较少的心肌重量。肝脏在现代系中更早成熟，这可能改善了营养物质的利用，因为鸟类从富含脂质的饲料转向富含碳水化合物的饲料。最后，现代系的空肠和回肠肠段长 20%，这可能允许增加营养物质的吸收。
