An estrus notifying apparatus (104) receives, via a relay device (102) and from communications devices (101) respectively attached to livestock animals (A) raised on a farm (F), measurement result information indicating measurement results of step counts for the livestock animals (A). The estrus notifying apparatus (104), based on measurement result information, respectively determines whether each of the livestock animals (A) is in estrus. If among the livestock animals (A), a given livestock (A1) is determined to be in estrus, the estrus notifying apparatus (104) determines whether the current time is included in the working hours of a worker (W). If the current time is included in the working hours, the estrus notifying apparatus 104) determines whether other livestock animals (A) near the given livestock animal (A1) have a possibility of being in estrus. If a livestock animal (A2) having a possibility of being in estrus is present, the estrus notifying apparatus (104) notifies the worker W of identification information for the given livestock animal (A1) and for other livestock animals (A2) near the given livestock animal (A1) and having the possibility of being in estrus.
