Significant Improvement in Survival of Tabby Jimpy Mutant Mice by Providing Folded-paper Nest Boxes
There is little scientific evidence that environmental enrichment meets the physiological needs for laboratory animals. The purpose of this study was to evaluate whether the provision of nest boxes improved the lifespan of Tabby jimpy (Ta-jp) mutant mice carrying a lethal gene. Nest boxes tested in this study were small folded-paper trapezoid-shaped houses. The Nest box group was reared in cages with the nest boxes and the Control group was raised in only standard cages. Weaning results and survival rates in Ta-jp mice were compared between both groups. By the weaning stage, all of the Ta-jp mice survived in the Nest box group. There was a significant difference in weaning rates between both groups. The body weight of weanlings demonstrated a significant difference between both groups. The survival analysis indicated that the Nest box group (29.9 days) significantly had a longer lifespan than the Control group (25.7 days). The Nest box group developed few abnormal jumping behaviours. The nest boxes served as shelters from environmental stimuli. In conclusion, we confirmed that folded-paper nest boxes had a beneficial effect on weaning rates of Ta-jp mice. Our results revealed that there was significant improvement in survival of Ta-jp mice using the nest boxes.