Animal Welfare Program, University of British Columbia, 2357 Main Mall, Vancouver, BC, V6T 1Z4, Canada.
Department of Environmental Studies, New York University, 285 Mercer St, New York City, NY, 10003, USA.
Sci Rep. 2019 Apr 16;9(1):6179. doi: 10.1038/s41598-019-42512-3.
Laboratory mice (Mus musculus) are typically housed in simple cages consisting of one open space. These standard cages may thwart mouse ability to segregate resting areas from areas where they eliminate, a behaviour that is prevalent across the animal kingdom. No scientific work has directly tested whether mice engage in such segregation behaviour, or whether the ability to do so may have welfare consequences. Here we show that mice, whether housed in standard cages or a complex housing system consisting of three interconnected standard cages, kept nesting and elimination sites highly segregated, with nest and urine co-occurring in the same location only 2% of the time. However, mice in the complex system established these clean and dirty sites in separate cages instead of separate locations within one cage, and carried bedding materials (cellulose pellets) from their nesting cages to their latrine cage. Moreover, mice in the complex system displayed more behaviours associated with positive welfare and were less disturbed by weekly husbandry procedures. We conclude that mice find waste products aversive, and that housing mice in a way that facilitates spatial segregation provides a simple way of allowing the expression of natural behaviours and improving welfare.
实验小鼠（Mus musculus）通常被安置在简单的笼子中，这些笼子只有一个开放空间。这些标准笼子可能会阻碍老鼠将休息区与排泄区分隔开来，而这种行为在动物王国中非常普遍。没有科学研究直接测试老鼠是否会进行这种隔离行为，或者这种行为能力是否会对其福利产生影响。在这里，我们发现无论将小鼠饲养在标准笼子中还是由三个相互连接的标准笼子组成的复杂饲养系统中，它们都会将巢穴和排泄区分开，巢和尿液同时出现在同一个位置的概率仅为 2%。然而，在复杂系统中的小鼠会将干净和肮脏的地方分别安置在不同的笼子里，而不是一个笼子的不同位置，并且会将床上用品（纤维素颗粒）从巢穴笼子带到厕所笼子。此外，在复杂系统中的小鼠表现出更多与积极福利相关的行为，并且对每周的饲养程序的干扰较小。我们的结论是，小鼠会将废物视为厌恶物，而通过促进空间隔离来饲养小鼠，可以为表达自然行为和提高福利提供一种简单的方法。
