PROBLEM TO BE SOLVED: To provide a nose ring capable of stably measuring a body temperature of cattle without battery replacement.SOLUTION: The nose ring 1 includes: a first heat absorbing part 11 for conducting heat of the outside air； a second heat absorbing part 12 for conducting heat inside the nose of the cattle； a heat insulating material 13 for insulating heat conduction between the first heat absorbing part and the second heat absorbing part； and a thermoelectric element 21 for generating power according to the temperature difference between the first heat absorbing part and the second heat absorbing part. Further, the nose ring includes a power source part 22 for pressurizing power generated by the thermoelectric element and outputting the pressurized power at a predetermined level, and a temperature sensor 24 for measuring the heat conducting the second heat absorbing part as the body temperature of the cattle using the power supply from the power source part. Further, the nose ring includes a radio part 26 for transmitting the body temperature of the cattle measured by the measurement sensor by radio using the power supply from the power source part.
