Skurnack Alexis M E, Lane Shawn P, Garman Lori, Burke Amy L, Williams Wendy R, Budda Madeline L
Division of Comparative Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
J Am Assoc Lab Anim Sci. 2024 Aug 14;63(5):504-12. doi: 10.30802/AALAS-JAALAS-24-040.
Some mice demonstrate excessive food-grinding behaviors in which food pellets are broken down into crumbs (orts). This is considered abnormal behavior and is undesirable in a research environment, as it is thought to potentially be a stereotypic behavior suggestive of a negative welfare state in these animals. Further, food grinding often necessitates more frequent food and bedding changes. Research outcomes may also be affected if investigators do not exclude food losses due to grinding when measuring food consumption. We hypothesized some mice may excessively grind food in part to expend energy and access to a running wheel would contribute to a reduction in food grinding. Total daily food usage (the combined weight of food consumption and ort production) was measured for 40 d in CD-1 mice that exhibited food grinding. Median daily food usage was compared 10 d before, 20 d during, and 10 d after access to a running wheel. Additional cages of similar food-grinding mice that did not have access to a running wheel were monitored during the same period for comparison. A significant reduction in food usage was observed in 8 out of the 20 d in which mice had access to a running wheel compared with controls ( < 0.05). This reduction was significantly less than the median daily food usage before and after the running wheels were available ( < 0.01). Food usage significantly increased sharply in the 3 d following removal of the running wheel compared with controls during the same period ( < 0.05). A positive correlation between relative humidity and median daily food usage was observed ( < 0.05). Despite fluctuations in relative humidity, providing a running wheel effectively reduced excessive food-grinding behavior.
一些小鼠表现出过度的食物研磨行为，即食物颗粒被分解成碎屑（残食）。这被认为是异常行为，在研究环境中是不可取的，因为它被认为可能是一种刻板行为，暗示这些动物处于负面的福利状态。此外，食物研磨通常需要更频繁地更换食物和垫料。如果研究人员在测量食物消耗时不排除因研磨导致的食物损失，研究结果也可能受到影响。我们假设一些小鼠可能会过度研磨食物，部分原因是为了消耗能量，而提供一个跑步轮将有助于减少食物研磨。对表现出食物研磨行为的CD-1小鼠的每日食物总用量（食物消耗和残食产生的总重量）进行了40天的测量。在提供跑步轮之前10天、提供期间20天和之后10天，比较了每日食物用量的中位数。同期对另外一些没有跑步轮的类似食物研磨小鼠的笼子进行监测以作比较。与对照组相比，在小鼠可以使用跑步轮的20天中有8天观察到食物用量显著减少（<0.05）。这种减少明显小于提供跑步轮之前和之后的每日食物用量中位数（<0.01）。与同期对照组相比，在移除跑步轮后的3天内，食物用量显著急剧增加（<0.05）。观察到相对湿度与每日食物用量中位数之间存在正相关（<0.05）。尽管相对湿度有波动，但提供一个跑步轮有效地减少了过度的食物研磨行为。
