An animal breeding system according to an embodiment includes a rack, a carrier robot, a thermo camera, and an instruction unit. The rack contains therein a cage for breeding an animal. The carrier robot includes a hand having a retention mechanism for the cage. The thermo camera is provided near the hand. The instruction unit instructs the carrier robot to perform an operation of taking the cage in and out from the rack while retaining the cage with the hand to carry the cage between the rack and a certain carrying position and an operation of bringing the thermo camera close to the cage in the rack to cause the thermo camera to capture the inside of the cage.