Mace Jenny L, Knight Andrew
Centre for Animal Welfare, Faculty of Health and Wellbeing, University of Winchester, Sparkford Road, Winchester SO22 4NR, UK.
Animals (Basel). 2022 Oct 30;12(21):2988. doi: 10.3390/ani12212988.
There is growing interest in keeping meat chickens in modern colony cages (CCs) rather than conventional litter-floor barns. Suggested welfare improvements for chickens in such systems include reduced bodily lesions due to lower contact with flooring contaminated with faeces and urine, due to slatted flooring and automated faeces removal. This systematic review sought to determine the animal welfare impacts of CCs using slatted flooring, in comparison to litter-based non-cage systems. Overall, 23 relevant studies were retrieved. From one perspective, the extant research appeared mixed. Fifteen (65%) of these 23 studies identified some form of welfare concern about slatted floors, and thus CCs. Yet, when considering actual welfare indicators assessed, the tallies generated in favour of each housing system were similar. Crucially however, there were incomplete behavioural welfare measures in 100% of the empirical studies reviewed. Accordingly, significant welfare concerns exist about CCs, centring around behavioural deprivation. Given that over 70 billion chickens are farmed then slaughtered each year globally, widespread implementation of CCs would create a major animal welfare concern. Instead of implementing such CC systems, research and development is recommended into improving welfare outcomes of conventional litter barns using different forms of commercially feasible enrichment. As a minimum, a full behavioural analysis, as detailed in the Welfare Quality Assessment protocols, should form a mandatory part of any future studies aimed at assessing the welfare impacts of housing systems on farmed chickens.
相较于传统的垫料地面鸡舍，越来越多的人对将肉鸡饲养在现代群体笼（CCs）中感兴趣。对于此类系统中的鸡，建议的福利改善措施包括：由于板条地面和自动粪便清除，减少了与被粪便和尿液污染的地面接触，从而减少身体损伤。本系统综述旨在确定与基于垫料的非笼养系统相比，使用板条地面的CCs对动物福利的影响。总体而言，共检索到23项相关研究。从一个角度来看，现有研究结果不一。这23项研究中有15项（65%）发现了对板条地面以及因此对CCs的某种形式的福利担忧。然而，在考虑实际评估的福利指标时，支持每种饲养系统的统计结果相似。但至关重要的是，在所有被审查的实证研究中，行为福利措施均不完整。因此，围绕行为剥夺，CCs存在重大的福利问题。鉴于全球每年有超过700亿只鸡被养殖然后屠宰，CCs的广泛应用将引发重大的动物福利问题。不应实施此类CC系统，建议开展研发工作，通过不同形式的商业上可行的丰富环境来改善传统垫料鸡舍的福利结果。至少，如福利质量评估协议中详细说明的全面行为分析，应成为未来任何旨在评估饲养系统对养殖鸡福利影响的研究的强制性组成部分。
