The invention relates to a device for permanently detecting the gastric pressure, the gastric temperature, the gastric motility and the movement of a livestock animal, in particular a ruminant, comprising a, for example, bolus-shaped body (14), said body (14) comprising the following components: a pressure sensor (9), a telemetric device (9) for transmitting measuring values, and a gas-tight interior space (12), wherein a wall of the gas-tight interior space (12) comprises in some regions an elastic material which is deformable by the gastric pressure of a livestock animal, and wherein the pressure sensor (9) is designed to detect the pressure in the gas-tight interior space (12). According to the invention, said device is designed such that it permanently remains in the stomach of the livestock animal when it is applied to the livestock animal.
