Craig J V, Swanson J C
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
Poult Sci. 1994 Jul;73(7):921-38. doi: 10.3382/ps.0730921.
The wild ancestors of chickens, along with those of most other farm animals, were preadapted to domestication because their lack of specialized requirements allowed them to adapt to a wide variety of environments provided by humans. Currently most commercial chickens kept for table-egg production are incubated, reared, and maintained as productive adults in high-density, artificial environments. Nevertheless, there are limits to adaptability as indicated by behavioral, physiological, immunological, and individual productivity indicators when environmental conditions become extreme. However, with the exception of obvious injury, no single criterion is likely to be adequate. Multiple indicators are required to obtain reliable evaluation of whether husbandry practices and environmental conditions reduce hens' welfare significantly. Concern for the well-being of hens has led to the phasing out of cages in two European countries. Although cages are known to be associated with some problems of well-being, it is known also that they have some welfare advantages for hens over alternative systems of production and they have definite economic advantages for producers. Therefore, it is doubtful whether the use of cages should be denied without exploring further the possibilities of cage modification or genetic selection aimed at improving the well-being of hens in such environments. Ethical perspectives relative to animals have been evolving since the time of Aristotle more than 300 yr B.C. Recent developments include divergence of welfare concerns between utilitarian and animal rights based philosophies. The utilitarians generally agree that animals may be used for human benefit if unnecessary pain and suffering are avoided and humane care and management criteria are met. Fundamentally, rights-oriented groups reject such exploitation. The general public exhibits a continuum of attitudes towards animals. However, there are indications that they are moving towards a protectionist attitude toward farm animals. Many requirements for good husbandry are known. However, uncertainty prevails in some areas, particularly with the necessity of routine procedures such as beak trimming and the amount of space needed, optimal group size, and whether nests, roosts, litter, and other quality of environment features are necessities or luxuries in terms of hens' welfare. Floor and feeder space and group size seem to be of paramount importance, and space that is adequate for well-being seems to be greater than that which yields the greatest net income. Genetic solutions to several behavior-related problems that compromise hens' well-being seem to be feasible and worthy of greater emphasis by commercial poultry breeders.
鸡以及大多数其他农场动物的野生祖先，预先适应了驯化，因为它们没有特殊的需求，这使它们能够适应人类提供的各种各样的环境。目前，大多数用于产食用蛋的商业鸡在高密度的人工环境中孵化、饲养并作为有生产力的成年鸡饲养。然而，当环境条件变得极端时，行为、生理、免疫和个体生产力指标表明其适应性是有限的。然而，除了明显的损伤外，没有单一的标准可能是足够的。需要多个指标来可靠地评估饲养管理措施和环境条件是否会显著降低母鸡的福利。对母鸡福利的关注导致两个欧洲国家逐步淘汰了笼子。虽然已知笼子与一些福利问题有关，但也知道它们相对于其他生产系统对母鸡有一些福利优势，并且对生产者有明确的经济优势。因此，在没有进一步探索旨在改善此类环境中母鸡福利的笼子改造或基因选择可能性的情况下，是否应该禁止使用笼子是值得怀疑的。自公元前300多年的亚里士多德时代以来，与动物相关的伦理观点一直在演变。最近的发展包括功利主义和基于动物权利的哲学之间在福利问题上的分歧。功利主义者普遍同意，如果避免不必要的痛苦和苦难并符合人道护理和管理标准，动物可以用于人类利益。从根本上说，以权利为导向的团体拒绝这种剥削。公众对动物表现出一系列态度。然而，有迹象表明他们正朝着对农场动物的保护主义态度转变。许多良好饲养管理的要求是已知的。然而，在一些领域仍然存在不确定性，特别是诸如断喙等常规程序的必要性以及所需的空间量、最佳群体规模，以及就母鸡福利而言，巢穴、栖木、垫料和其他环境质量特征是必需品还是奢侈品。地面和采食空间以及群体规模似乎至关重要，并且足以保障福利的空间似乎大于能产生最大净收入的空间。针对几个损害母鸡福利的行为相关问题的基因解决方案似乎是可行的，值得商业家禽育种者给予更多重视。
