PROBLEM TO BE SOLVED: To easily clean a rear face of a floor drainboard which is laid on a bottom of a cage main body.SOLUTION: A floor drainboard 1 laid on a bottom of a cage main body is composed of a plurality of drainboard materials 4, and a plurality of connecting parts for connecting both opposing drainboard materials. The respective drainboard materials 4 are extended in a longitudinal direction DX, aligned in parallel at equal intervals along a transverse direction DY, and form a bamboo blind shape. The opposing drainboard materials 4 are connected to each other by joint pipe parts 5A, 5B, 6A, 6B and 7A, 7B and exposure parts of rubber-made rod-shaped bodies 8, 9 and 10 which are fit into through holes of the drainboard materials 4. The exposure parts form bendable elastic body parts. By lifting and pulling up the floor drainboard 1 from one end of the floor drainboard 1, the rubber-made exposure parts of the respective connecting parts at one-end sides are sequentially bent, the floor drainboard 1 is brought into a rolled-up state, and a rear face of the floor drainboard 1 is exposed.
