The following are known Action Replay Codes for Zoo Keeper on Nintendo DS (NDS).

Game ID: AZKE-DD24DF4F

Infinite Time (Zoo Keeper/Tokoton/TA Modes)
92062200 00000202
62062230 00000000
b2062230 00000000
10000000 00007000
10000004 00007000
d2000000 00000000

Infinite Time (Story)
92062200 00000101
620621f8 00000000
b20621f8 00000000
10000000 00007000
10000004 00007000
d2000000 00000000