Kasanen I H E, Inhilä K J, Vainio O M, Kiviniemi V V, Hau J, Scheinin M, Mering S M, Nevalainen T O
National Laboratory Animal Center, University of Kuopio, Kuopio, Finland.
Lab Anim. 2009 Jul;43(3):215-23. doi: 10.1258/la.2008.008066. Epub 2009 Feb 23.
Laboratory rats are commonly fed ad libitum (AL). Moderate dietary restriction (DR) decreases mortality and morbidity when compared with AL feeding, but there are several obstacles to the implementation of DR. Traditional methods of restricted feeding disrupt normal diurnal eating rhythms and are not compatible with group housing. We have designed a novel method, the diet board, to restrict the feeding of group-housed rats. Animals fed from the diet board had 15% lower body weight than the AL-fed animals at the age of 17 weeks. The welfare effects of diet board feeding were assessed by comparing the stress physiology of diet board fed animals with that of AL-fed animals. Diet board feeding was associated with higher serum corticosterone levels and lower faecal secretion of IgA, suggesting the diet board causes a stress reaction. However, the AL-fed group had larger adrenal glands with higher adrenaline and noradrenaline content than the diet board animals. No gastric ulcers were found in any of the animals at necropsy. The diet board thus appears to cause a stress reaction when compared with AL-fed rats, but no apparent pathology was associated with this reaction. The diet board could help to solve the health problems associated with AL feeding, while allowing the rats to be group-housed and to maintain their normal diurnal eating rhythms. The diet board can also be seen as a functional cage furniture item, dividing the cage into compartments and thus increasing the structural complexity of the environment. In conclusion, the diet board appears to possess refinement potential compared with traditional methods of DR.
实验大鼠通常自由采食（AL）。与自由采食相比，适度饮食限制（DR）可降低死亡率和发病率，但实施饮食限制存在一些障碍。传统的限制喂养方法会打乱正常的昼夜进食节律，且不适用于群居饲养。我们设计了一种新方法——饮食板，用于限制群居大鼠的进食。在17周龄时，通过饮食板进食的动物体重比自由采食的动物低15%。通过比较饮食板喂养动物与自由采食动物的应激生理学来评估饮食板喂养的福利效果。饮食板喂养与较高的血清皮质酮水平和较低的粪便IgA分泌有关，这表明饮食板会引发应激反应。然而，自由采食组的肾上腺比饮食板喂养的动物更大，肾上腺素和去甲肾上腺素含量更高。尸检时在任何动物中均未发现胃溃疡。因此与自由采食的大鼠相比，饮食板似乎会引发应激反应，但这种反应未伴有明显的病理学变化。饮食板有助于解决与自由采食相关的健康问题，同时允许大鼠群居并维持其正常的昼夜进食节律。饮食板也可被视为一种功能性笼具，将笼子分隔成多个区域，从而增加了环境的结构复杂性。总之，与传统的饮食限制方法相比，饮食板似乎具有优化潜力。
