Solid floor versus wire floor housing for rats revisited: influence of age and the presence of nest boxes

摘要

Some studies have shown that laboratory rats prefer to dwell on solid rather than wire floors, and like to use nest boxes and nesting material. To test these conclusions under our conditions, we determined the resting preference of rats in a system ofthree joined cages, of which two contained wire floors, one of these with food and water, and the other a solid floor with bedding but without food and water. Two experiments were conducted for each group, with and without nest boxes placed into the system, and the rats had simultaneous access to all three cages containing the above mentioned elements. Two groups were investigated with the first one consisting of twelve adult male and twelve adult female Wistar rats, and the second of twelve adolescentmales and twelve adolescent females. Four animals were placed into the cage system at a time for 10 days, and were observed at the same time every day, every sixty minutes for six hours. The experiments were conducted during the light period and repeated three times, making it a total of 180 observations per group. The data did not reveal a clear preference for solid floors. On the contrary, juveniles were found most often on wire floors while amongst the adults, a preference for solid floors was apparent only in females, and only when a nest box was available. Nest boxes were preferred by all ages and sexes.