Data_Sheet_1_Welfare issues and potential solutions for laying hens in free range and organic production systems: A review based on literature and interviews.PDF

In free-range and organic production systems, hens can make choices according to their needs and desires, which is in accordance with welfare definitions. Nonetheless, health and behavioral problems are also encountered in these systems. The aim of this article was to identify welfare challenges observed in these production systems in the EU and the most promising solutions to overcome these challenges. It is based on a review of published literature and research projects complemented by interviews with experts. We selected EU specific information for welfare problems, however, the selected literature regarding solutions is global. Free range use may increase the risk of infection by some bacteria, viruses and parasites. Preventive methods include avoiding contamination thanks to biosecurity measures and strengthening animals' natural defenses against these diseases which can be based on nutritional means with new diet components such as insect-derived products, probiotics and prebiotics. Phytotherapy and aromatherapy can be used as preventive and curative medicine and vaccines as alternatives to antibiotics and pesticides. Bone quality in pullets and hens prevents keel deviations and is favored by exercise in the outdoor range. Free range use also lead to higher exposure to variable weather conditions and predators, therefore shadow, fences and guard animals can be used to prevent heat stress and predation respectively. Granting a free range provides opportunities for the expression of many behaviors and yet many hens usually stay close to the house. Providing the birds with trees, shelters or attractive plants can increase range use. Small flock sizes, early experiences of enrichment and personality traits have also been found to enhance range use. Severe feather pecking can occur in free range production systems, although flocks using the outdoor area have better plumage than indoors. While many prevention strategies are facilitated in free range systems, the influence of genetics, prenatal and nutritional factors in free range hens still need to be investigated. This review provides information about practices that have been tested or still need to be explored and this information can be used by stakeholders and researchers to help them evaluate the applicability of these solutions for welfare improvement.

在散养与有机养殖体系中，家禽可依据自身需求与意愿进行行为选择，这符合动物福利的定义标准。尽管如此，此类养殖体系中仍会出现健康与行为层面的问题。本研究旨在明确欧盟范围内此类养殖体系中存在的动物福利挑战，以及破解这些挑战的最优可行方案。本研究基于已发表的文献与科研项目综述，并辅以专家访谈进行补充完善。我们针对动物福利问题仅选取欧盟范围内的相关信息，但关于解决方案的文献则覆盖全球范围。家禽使用户外散养区域可能会提升其感染部分细菌、病毒与寄生虫的风险。预防性防控手段包括通过生物安全措施避免污染，以及增强家禽对这类疾病的天然抵抗力——后者可通过营养调控实现，例如添加昆虫源产品、益生菌与益生元等新型日粮成分。植物疗法与芳香疗法可作为预防与治疗药物，疫苗则可替代抗生素与杀虫剂使用。青年母鸡与成年母鸡的骨骼健康可防止龙骨变形，而户外散养的运动能够改善骨骼质量。家禽使用户外散养区域还会使其更易受到多变天气与天敌的威胁，因此可分别通过设置遮阳设施、围栏与护卫动物来缓解热应激与防范天敌。开放户外散养区域为家禽提供了表达多种自然行为的机会，但多数家禽通常仍会选择紧邻鸡舍的区域活动。为家禽提供树木、遮蔽设施或具有吸引力的植被，可提升其对户外散养区域的使用率。研究还发现，较小的鸡群规模、早期丰富化饲养经历以及家禽自身的个性特征，均可提升其户外散养区域的使用率。尽管使用户外区域的鸡群羽毛状态优于舍内养殖鸡群，但散养体系中仍可能出现严重的啄羽行为。尽管散养体系中可便捷实施多种防控策略，但遗传因素、产前环境与营养水平对散养家禽的影响仍有待进一步研究。本综述汇总了已验证的实践方案与仍待探索的研究方向，相关信息可供利益相关方与科研人员参考，以评估这些解决方案在改善动物福利方面的适用性。