While the scale of dairy farming and the like has increased, the problem of a shortage of labor has arisen. The physical condition and the management of activity of cattle as livestock are in danger of being neglected because of the shortage of labor. This problem gives rise to effects on the management of cattle reproduction and diseases, and by extension, lowers the productivity efficiency for milk, beef and the like. An activity/state management system for cattle according to an embodiment of the present invention has: an activity/state sensor module attached to a cow within a management area, said activity/state sensor module being provided with a triaxial acceleration sensor; and an activity/state determination unit for determining a plurality of activities/states of the cow on the basis of measurement values for the triaxial acceleration sensor, which indicate different measurement patterns for each of the plurality of activities/states of the cow.
