The utilization of male chickens for fattening constitutes a potential advantage of the dual-purpose concept. In addition to the use of commercial hybrids, producers could introduce alternative chicken genotypes or further develop local breeds. To gain more information about the genetic effect on growth performance, carcass characteristics, physicochemical meat traits, and sensory attributes, 60 cockerels belonging to Les Bleues (developed from the French breed Bresse Gauloise), Canarian (Spanish local breed), and Dominant Red Barred D459 (DRB D459; commercial dual-purpose hybrid) genotypes were reared under free-range conditions in a warm tropical climate and slaughtered at 15 wk of age. The major findings were as follows: (i) Les Bleues chickens exhibited the best growth rate and the body weight of 2.44 kg reached by this strain at 15 wk would be gained only after 18 to 19 wk with DRB D459 and it would take even 2 wk longer for Canarian breed, according to the growth modeling using the Morgan equation, although the body weights between the latter were statistical similar at 15 wk; (ii) Les Bleues strain had a good capability in terms of meat production performance, presenting carcasses with significantly heavier commercial cuts, and higher fleshiness than the other 2 genotypes; (iii) although significant differences among genotypes appeared in the physical characteristics of the breast meat, especially those concerning the skin and meat color and water-holding capacity, which was significantly reduced for Canarian chickens, no significant differences were detected in the chemical composition and fatty acid profile of the breast meat; (iv) trained panelists (n = 8) pointed out that leg meat of none of the genotypes is better in terms of global appreciation, but untrained consumers (n = 99) perceived that the Les Bleues leg meat was significantly more palatable than the DRB D459 leg meat.

中文翻译：

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3 种不同遗传来源的两用公鸡在自由放养条件下育肥的适宜性。

利用公鸡进行育肥是两用概念的潜在优势。除了使用商业杂交种外，生产者还可以引入替代鸡基因型或进一步开发本地品种。为了获得更多关于遗传对生长性能、胴体特征、肉质理化性状和感官属性的影响的信息，60 只公鸡属于 Les Bleues（从法国品种 Bresse Gauloise 发展而来）、Canarian（西班牙本地品种）和占主导地位的 Red Barred D459（DRB D459；商业两用杂种）基因型在温暖的热带气候下的自由放养条件下饲养，并在 15 周龄时屠宰。主要发现如下： (i) Les Bleues 鸡的生长速度最好，体重为 2。根据使用摩根方程的生长模型，这种菌株在 15 周时达到 44 公斤，仅在使用 DRB D459 后 18 到 19 周后才会增加，加那利品种甚至需要更长的 2 周时间，尽管后者之间的体重在 15 周时统计相似；(ii) Les Bleues 品系在肉类生产性能方面具有良好的能力，与其他 2 个基因型相比，具有明显更重的商业切割和更高的肉质；(iii) 虽然基因型之间在胸肉的物理特性上出现了显着差异，尤其是在皮肤和肉色以及持水能力方面，加那利鸡显着降低，但在化学成分和化学成分上没有发现显着差异。胸肉的脂肪酸谱；