Abstract The aim of the study was to determine the effect of caponizing on body weight and physicochemical properties of meat of the capons – hybrids obtained from the crossing of hens of the Yellowleg Partridge (Ż-33) breed with meat roosters. The study covered 80 hybrid roosters, which were randomly assigned to two groups of 40 animals each (8 boxes of 10 birds in each group). Group I (control) consisted of uncastrated roosters while group II included birds, which were castrated at 8 weeks of age under local anaesthesia by a vet. Birds were fed ad libitum with the same standard diets and kept on litter under optimal environmental conditions with a stocking density of 7 animals/ m2. At the end of fattening, i.e. in the 20th week of life, 8 birds with a body weight close to the group average were selected from each group for slaughter. After slaughter, the effectiveness of the procedure was checked (lack of testicles), then the slaughter performance of birds, physicochemical parameters of the pectoral and leg muscles were determined, and sensory evaluation was performed. The procedure of castration of hybrid roosters had a positive effect on body weight, feed conversion ratio and carcass traits. The pectoral and leg muscles of the capons were characterized by better water absorption, tenderness and sensory evaluation compared to roosters. Among the assessed groups of birds there was also a variation in the colouring of whole carcasses and muscles, which were lighter (L*), more yellow (b*) and less red (a*) in caponized birds. In addition, the castration procedure had a positive effect on the total protein content in both the pectoral and leg muscles, which in turn, with a higher raw fat content, were distinguished by a favourable ratio of n-6/n-3 polyunsaturated fatty acids (PUFA). Based on the results, it can be concluded that the hybrids obtained from the crossbreeding of the Yellowleg Partridge (Ż-33) and Ross 308 meat roosters are good choice for capon production. They can complement poultry meat production with a niche product for consumers looking for products of exceptional quality.

中文翻译：

---

皂化对杂交鸡生长性能和肉理化特性的影响

摘要 本研究的目的是确定公鸡化对公鸡体重和肉理化特性的影响 - 从黄腿鹧鸪 (Ż-33) 品种的母鸡与肉公鸡杂交获得的杂种。该研究涵盖了 80 只杂交公鸡，它们被随机分配到两组，每组 40 只动物（每组 8 箱，每组 10 只鸟）。第 I 组（对照）由未阉割的公鸡组成，而第 II 组包括鸟类，它们在 8 周龄时由兽医在局部麻醉下阉割。用相同的标准饮食随意喂养鸟类，并在最佳环境条件下饲养垫料，饲养密度为 7 只/平方米。在育肥结束时，即在生命的第 20 周，从每组中选出 8 只体重接近该组平均水平的鸡进行屠宰。屠宰后，检查程序的有效性（缺乏睾丸），然后测定家禽的屠宰性能、胸肌和腿部肌肉的理化参数，并进行感官评价。杂交公鸡阉割程序对体重、饲料转化率和胴体性状有积极影响。与公鸡相比，公鸡的胸肌和腿部肌肉具有更好的吸水性、触痛和感官评价。在评估的鸟类群体中，整个尸体和肌肉的颜色也存在差异，在阉割的鸟类中，它们更亮（L*）、更黄（b*）和更少红色（a*）。此外，阉割程序对胸肌和腿部肌肉的总蛋白质含量有积极影响，反过来，n-6/n-3 多不饱和脂肪酸 (PUFA) 的比例良好。根据结果​​可以得出结论，黄腿鹧鸪（Ż-33）和罗斯308肉公鸡杂交获得的杂交种是生产鲤科鱼类的不错选择。他们可以为寻求卓越品质产品的消费者提供利基产品来补充禽肉生产。