Slow-growing broilers have less problem in locomotives and enable to make chicken meat with more preference to animal welfare

<p>Although in some European countries, slow-growing broilers are increasing in number, corresponding to the demands for animal welfare, it is unpopular in Japan. Therefore, the concept of slow-growing broilers needs to be accepted by more Japanese farmers and consumers. Here, branded commercial chicken, produced by crossing two breeds of slow-growing broilers, were raised, and growth performance, the soundness of locomotives, behaviors, and anatomical traits were assessed and compared with those of fast-growing broilers.</p><p>Compared with the fast-growing broilers, the slow-growing broilers showed significantly lighter body weights and daily weight gain. The gait scores, valgus angles, and scores of breast plumage dirtiness were significantly lower in the slow-growing broilers. Based on our behavioral observation, the slow-growing broilers spent significantly more time moving and standing. Lastly, we conducted anatomical studies and discovered that the weights of the breast meat in the slow-growing broilers were significantly lighter. Additionally, the slow-growing broilers had heavier femur weights than the fast-growing broilers. From these studies, it was clarified that the deterioration of gait abilities was less in slow-growing broilers, implying that slow-growing broilers could be used to produce chicken meat with higher welfare levels.</p>