Riber Anja B, Hinrichsen Lena K
Department of Animal Science, Aarhus University, Tjele, Denmark.
Front Vet Sci. 2017 Dec 18;4:222. doi: 10.3389/fvets.2017.00222. eCollection 2017.
Beak trimming is used worldwide as a method of reducing the damage to feathers and skin caused by injurious pecking in laying hens. However, beak trimming also causes some welfare issues as trimming the beak results in pain and sensory loss. Due to this dilemma, there is an ongoing discussion in several European countries about whether to ban beak trimming. In this study, we investigated the welfare consequences of keeping layers with intact beaks and examined for links between injurious pecking damage and keel bone damage on an individual level. A study was conducted on 10 commercial farms housing laying hens in the barn system. Each farm participated with a flock of beak-trimmed hens (T) and a flock of non-trimmed (NT) hens that were visited around 32 and 62 weeks of age. During visits, the condition of plumage, skin, feet, and keel bone of 100 hens was assessed. Mortality was recorded by the producers. NT flocks had a lower prevalence of hens with good plumage condition around 32 weeks of age (94.1 vs. 99.6%, < 0.001) and a higher prevalence of hens with poor plumage condition at 62 weeks of age (63.6 vs. 15.2%, < 0.001) compared with T flocks. The prevalence of hens with keel bone deviations, with both keel bone fractures and deviations and with body wounds, was higher in NT flocks compared with T flocks at both ages ( < 0.001). Accumulated mortality from placement to end of production tended to be higher in NT flocks compared with T flocks (14.2 vs. 8.6%; = 0.06). The prevalence of keel bone damage was higher among hens with poor plumage condition than hens with moderate/good plumage condition (31.5 vs. 22.2%; < 0.001). Thus, omitting beak trimming had negative consequences for the condition of plumage, skin, and keel bone, and tended to increase mortality, highlighting the risk of reduced welfare when keeping layers with intact beaks. In addition, injurious pecking damage was found to be positively linked to keel bone damage. The causal relation is unknown, but we propose that fearfulness is an important factor.
断喙在全球范围内被用作减少蛋鸡因有害啄羽行为对羽毛和皮肤造成损伤的一种方法。然而，断喙也会引发一些福利问题，因为断喙会导致疼痛和感觉丧失。由于这一困境，几个欧洲国家正在就是否禁止断喙展开讨论。在本研究中，我们调查了饲养喙完整的蛋鸡的福利后果，并在个体层面上研究了有害啄羽损伤与龙骨骨折损之间的联系。对10个采用鸡舍系统饲养蛋鸡的商业农场进行了一项研究。每个农场都参与了，其中一群是断喙母鸡（T组），另一群是未断喙母鸡（NT组），在大约32周龄和62周龄时进行了走访。走访期间，对100只母鸡的羽毛、皮肤、脚部和龙骨的状况进行了评估。生产者记录了死亡率。与T组相比，NT组在32周龄左右羽毛状况良好的母鸡比例较低（94.1%对99.6%，P＜0.001），而在62周龄时羽毛状况较差的母鸡比例较高（63.6%对15.2%，P＜0.001）。在两个年龄段，NT组中龙骨有偏差、同时存在龙骨骨折和偏差以及身体有伤口的母鸡比例均高于T组（P＜0.001）。从入栏到生产结束，NT组的累计死亡率往往高于T组（14.2%对8.6%；P = 0.06）。羽毛状况差的母鸡中龙骨骨折损的比例高于羽毛状况中等/良好的母鸡（31.5%对22.2%；P＜0.001）。因此，不进行断喙对羽毛、皮肤和龙骨状况有负面影响，并且往往会增加死亡率，突出了饲养喙完整的蛋鸡时福利降低的风险。此外，发现有害啄羽损伤与龙骨骨折损呈正相关。因果关系尚不清楚，但我们认为恐惧是一个重要因素。
