Zawacki Zosia E, Sharpe James A, Porco Travis C, Lindstrom Krista E
Laboratory Animal Resource Center, University of California San Francisco, San Francisco, California; and.
Francis I. Proctor Foundation, University of California San Francisco, San Francisco, California.
J Am Assoc Lab Anim Sci. 2024 Aug 20;63(5):495-503. doi: 10.30802/AALAS-JAALAS-24-000010.
Feed wastage in laboratory mice, also known as chewing or grinding behavior, is problematic for program management and animal welfare. The destruction of pelleted feed without consumption produces a powder accumulation on the cage floor called orts. Ort accumulation disrupts the cage microenvironment and can clog Lixits resulting in flooding. Moreover, added labor adds cost, and cage disruption increases animal stress. Published studies examining the behavior and ways to mitigate it have had inconsistent results, and the cause or causes have not yet been fully identified. The purpose of this study was to identify methods to reduce the development of chewing behavior in laboratory mice. Female Swiss Webster (Tac:SW) mice ( = 144) were randomly assigned to one of 8 groups (12 cages per group) with 2 housing densities (single and pair) and 4 nesting material paradigms. Mice were housed on clean bedding for 8 wk and then soiled bedding for the next 8 wk. Chewing behavior was evaluated by feed weight, cage weight, and feed scores. The addition of a Diamond Twist significantly increased ort production, while nest transfer decreased it but not significantly. Pair housing increased overall orts but not when adjusted for animal number. These results identified potential contributing factors to chewing behavior. However, further research is needed to elucidate the exact causes and solutions.
实验小鼠的饲料浪费，也称为咀嚼或研磨行为，对项目管理和动物福利来说是个问题。未被食用的颗粒饲料被破坏后会在笼底产生粉末堆积，称为残食。残食堆积会破坏笼内微环境，并可能堵塞饮水器导致漏水。此外，额外的劳动会增加成本，而笼内环境的破坏会增加动物的应激反应。已发表的研究在考察这种行为及其缓解方法时，结果并不一致，其原因尚未完全明确。本研究的目的是确定减少实验小鼠咀嚼行为发生的方法。将144只雌性瑞士韦伯斯特（Tac:SW）小鼠随机分为8组（每组12个笼子），设置2种饲养密度（单只和成对）以及4种筑巢材料模式。小鼠先在干净垫料上饲养8周，然后在接下来的8周使用脏垫料。通过饲料重量、笼子重量和饲料评分来评估咀嚼行为。添加菱形编织物显著增加了残食产生量，而更换巢穴可使其减少，但不显著。成对饲养会增加总体残食量，但按动物数量调整后则不然。这些结果确定了咀嚼行为的潜在影响因素。然而，仍需要进一步研究以阐明确切原因和解决办法。
