Faculty of Science and Technology, Free University of Bolzano, Piazza Universitá 5, 39100 Bolzano, Italy.
Poult Sci. 2018 Oct 1;97(10):3564-3576. doi: 10.3382/ps/pey223.
Dual-purpose chicken where both sexes are reared together, before males are separated for final fattening, while females are kept for an entire laying period, may provide an economic alternative under certain production and marketing conditions. Two genotypes, purebred Bresse-Gauloise (PURE, n = 300) and crossbred Bresse-Gauloise × New Hampshire (CROSS, n = 300), were compared. One-day-old mixed-sex chicken were raised for 12 wk under floor husbandry conditions on a broiler diet. Thereafter, males were transferred to a mobile chicken house with free-range access. Males were slaughtered at weekly intervals from 12th to 19th wk of age. Hens were kept for 1 laying period in a mobile house. Growth performance, feed consumption, carcass, meat quality, health and welfare traits were measured in both sexes. In females layers' performance, egg quality and behavior were recorded, too. At 12 wk, males of PURE reached a live weight of 2,075 g and CROSS of 1,865 g (P < 0.05), while at 16 wk both weighed more than 2,500 g (P > 0.05). Dressing percentage increased with slaughter age and was above 68% in both genotypes when slaughtered at 18 to 19 wk of age. Proportion of legs, breast, and wings was 34.3, 16.0, and 11.0% in PURE and 34.7, 15.5, and 12.1% in CROSS (P > 0.05). Laying performance was 54.5% in PURE and 54.2% in CROSS (P > 0.05). Egg breaking strength decreased during the laying period, but remained above 30 N. Feed conversion was 3.4 kg feed/kg egg. On average, 25% of the animals stayed outdoors during daytime (P > 0.05). Keel bone deformations were observed in 10% and breast blisters in 20% of the hens. Under the specific conditions of marketing products with added value, performances resulted in an overall economic benefit, which was higher for PURE than CROSS. The use of dual-purpose chicken to avoid the killing of 1-d-old chicken and mobile housing may substantiate premium prices in such a system.
雌雄混养的两用鸡，在雄性鸡被分开进行最后育肥之前，雌性鸡会一直被饲养以供整个产蛋期使用，在某些生产和营销条件下，这可能是一种经济的选择。本研究比较了两种基因型，纯bred Bresse-Gauloise（纯系，n = 300）和杂交 Bresse-Gauloise × New Hampshire（杂交系，n = 300）。1 日龄的混性别鸡在地板饲养条件下用肉鸡饲料饲养 12 周。此后，雄性鸡被转移到一个有自由放养通道的移动鸡舍。从第 12 周到第 19 周龄，雄性鸡每周屠宰一次。母鸡在一个移动鸡舍中饲养一个产蛋期。在两性鸡中测量了生长性能、饲料消耗、胴体、肉质、健康和福利性状。在产蛋母鸡中，还记录了产蛋性能、蛋品质和行为。在 12 周龄时，纯系雄性鸡的活重达到 2075 克，杂交系雄性鸡的活重达到 1865 克（P < 0.05），而在 16 周龄时，两者的体重均超过 2500 克（P > 0.05）。屠宰年龄越大，屠体率越高，当在 18 至 19 周龄时屠宰时，两种基因型的屠体率均超过 68%。腿、胸和翅膀的比例分别为纯系 34.3%、16.0%和 11.0%，杂交系 34.7%、15.5%和 12.1%（P > 0.05）。纯系母鸡的产蛋率为 54.5%，杂交系母鸡的产蛋率为 54.2%（P > 0.05）。鸡蛋的破蛋强度在产蛋期间下降，但仍保持在 30 牛以上。饲料转化率为 3.4 千克饲料/千克鸡蛋。平均而言，25%的动物在白天会在户外（P > 0.05）。在 10%的母鸡中观察到龙骨骨变形，在 20%的母鸡中观察到乳房水泡。在有附加值的产品营销的具体条件下，表现带来了整体经济效益，纯系比杂交系更高。使用两用鸡来避免宰杀 1 日龄鸡和移动鸡舍可以在这种系统中证明溢价的合理性。
