Tiemann Inga, Hillemacher Sonja, Wittmann Margit
Institute of Animal Science, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
Institute of Agricultural Engineering, University of Bonn, Nussallee 5, 53115 Bonn, Germany.
Animals (Basel). 2020 Oct 28;10(11):1980. doi: 10.3390/ani10111980.
Chickens are the world's most widely used farm animal and have a significant genetic diversity. In the current study, we investigated three strains for their suitability as dual-purpose chickens, with a focus on the fattening ability and welfare of the cockerels: 1. layer cockerels (Lohmann Brown, LB, = 714); 2. cockerels of a dual-purpose hybrid (Lohmann Dual, LD, = 844); and 3. cockerels of a native breed (Rhinelander, RL, = 458). Chicks were raised under identical conditions and marked individually to compare focus and random sampling methods for weighing birds weekly. Because chicks of dual-purpose origins are usually raised mixed-sex, cockerels and pullets were weighed and observed together until sexes the were identifiable at week 10 of their life. During the 10th to 20th week of life, investigations were continued on 100 cockerels per genotype. Key figures for growth performance, such as feed conversion ratio (FCR) and European production efficiency factor (EPEF), were also calculated at weekly intervals. LD cockerels showed considerable growth performance ( < 0.001 compared to LB, RL, 2 kg at 9 weeks), whereas LB reached a live weight of 2 kg at 13 weeks and RL at 15 weeks of age. Genotype-dependent differences were also evident, with favorable FCR and EPEF for LD, intermediate for LB, and unfavorable for RL (all < 0.001). The results of the FCR and EPEF suggest that cockerels should be slaughtered around week 8 of life, although only the carcass of the LD might be marketable. Thus, the optimal time of slaughter based on production parameters such as FCR and EPEF is different from the time when the animal reaches a marketable 2 kg live weight. Animal-based welfare indicators revealed that the RL are not adapted to production environments, including those that are extensive. Further research aimed at adapted feed management, including better FCR, and animals adapted to the respective production environments is necessary to improve alternative poultry production in the future.
鸡是世界上使用最广泛的农场动物，具有显著的遗传多样性。在本研究中，我们调查了三个品系作为兼用型鸡的适用性，重点关注公鸡的育肥能力和福利：1. 蛋用型公鸡（罗曼褐，LB，n = 714）；2. 兼用型杂交公鸡（罗曼兼用型，LD，n = 844）；3. 本地品种公鸡（莱茵兰，RL，n = 458）。雏鸡在相同条件下饲养并单独标记，以比较每周称重鸡的重点抽样和随机抽样方法。由于兼用型品系的雏鸡通常混养，公鸡和母鸡一起称重并观察，直到在其生命的第10周能够区分性别。在生命的第10至20周期间，对每种基因型的100只公鸡继续进行调查。生长性能的关键指标，如饲料转化率（FCR）和欧洲生产效率因子（EPEF），也每周进行计算。LD公鸡表现出相当好的生长性能（与LB、RL相比，P < 0.001，9周龄时体重达2 kg），而LB在13周龄时达到2 kg活重，RL在15周龄时达到。基因型依赖性差异也很明显，LD的FCR和EPEF良好，LB中等，RL不利（均P < 0.001）。FCR和EPEF的结果表明，公鸡应在生命的第8周左右屠宰，尽管只有LD的胴体可能适合上市。因此，基于FCR和EPEF等生产参数的最佳屠宰时间与动物达到2 kg可上市活重的时间不同。基于动物的福利指标显示，RL不适应生产环境，包括粗放型环境。未来需要进一步研究，旨在采用适应性饲料管理，包括更好的FCR，以及使动物适应各自的生产环境，以改善替代家禽生产。
