Biomedical Sciences, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada.
J Am Assoc Lab Anim Sci. 2022 Mar 1;61(2):140-148. doi: 10.30802/AALAS-JAALAS-21-000024. Epub 2022 Jan 26.
Laboratory rodent housing conditions vary significantly across laboratories and facilities. Variation in housing can be associated with animal stress leading to study variability and the subsequent inability to replicate experimental findings. Optimization and standardization of animal housing are necessary to promote animal welfare and data consistency, thereby reducing the number of animals necessary to detect treatment effects. While interest in environmental enrichment is increasing, many studies do not examine the behavior of animals in the home cage, neglecting important aspects of enrichment. To determine how increased vertical home cage area affects animal welfare, double-decker cages (enriched), which allow rats to upright stand, were compared with standard single-level cages, which impede the ability to upright stand. Home cage welfare was assessed by analyzing ultrasonic vocalizations, fecal corticosterone, upright standing, and fighting. Ultrasonic vocalization was further explored by analyses of call type as defined by a 14 call-type schematic. Rats housed in enriched cages spent more time fighting, produced fewer 50 kHz calls, and had higher levels of fecal corticosterone. Rats in standard cages attempted to upright stand more often but remained upright for a shorter amount of time due to the height limitation imposed by standard cages. In addition, standard cages restrict some naturalistic behaviors such as upright standing and reduce fighting, which may be attributable to their single-tier organization and floor space. Enriched cages permit rats to engage in normal ethological behavior but also increase fighting. This study demonstrates that housing conditions have a meaningful impact on multiple measures of animal affect. When considering study design, researchers should be aware of how housing conditions affect animal subjects.
实验室啮齿动物的饲养条件在不同的实验室和设施中存在显著差异。饲养条件的变化可能与动物的应激有关，从而导致研究结果的变异性和随后无法复制实验结果。优化和标准化动物饲养是促进动物福利和数据一致性的必要条件，从而减少检测治疗效果所需的动物数量。虽然人们对环境丰容的兴趣日益增加，但许多研究并没有检查动物在家庭笼中的行为，忽视了丰容的重要方面。为了确定增加垂直家庭笼面积如何影响动物福利，比较了双层笼（丰容），允许大鼠直立站立，与阻碍直立站立能力的标准单层笼。通过分析超声发声、粪便皮质酮、直立站立和战斗来评估家庭笼福利。通过对 14 种叫声类型示意图定义的叫声类型的分析，进一步探讨了超声发声。饲养在丰容笼中的大鼠打架时间更长，产生的 50 kHz 叫声更少，粪便皮质酮水平更高。标准笼中的大鼠更频繁地试图直立站立，但由于标准笼的高度限制，它们直立站立的时间更短。此外，标准笼限制了一些自然行为，如直立站立和减少战斗，这可能归因于它们的单层组织和占地面积。丰容笼允许大鼠进行正常的行为，但也会增加战斗。这项研究表明，饲养条件对动物影响的多个衡量标准有重要影响。在考虑研究设计时，研究人员应该意识到饲养条件如何影响动物实验对象。
