Apparatus and method for managing animals such as but not limited to livestock. An ear tag assembly (102, 400, 460, 480, 510) has a main body (120, 402), a backing member (130, 404) and a shaft (124, 408) that extends through an aperture through an outer ear (1 14, 1 86) of an animal (1 12) to interconnect the main body and the backing member. A primary temperature sensor (140, 436, 462, 484) obtains an outer ear temperature of the outer ear. An ambient temperature sensor (150, 406) obtains an ambient temperature of a surrounding environment external to the animal. A control circuit (170) receives the outer ear and ambient temperatures and determines a successful insemination of the animal has taken place by comparing the outer ear temperature and the ambient temperature over a selected time interval (506).
