A base transceiver station of a digital mobile telecommunication system comprising a master base transceiver station device and a plurality of remote radio frequency units separated from the master BTS device and installed at a remote site therefrom for processing radio frequency signals. The programmable memory is able to store corresponding account data and image data for a plurality of different accounts. The computer is suitable for determining the sub-period between the last supply of feed to an animal and the momentary point of time when the animal is identified by the animal identification system at the feeding parlour. Induced current flows to each of the reference coil and the detection coil due to magnetic flux generated as drive current flows to the drive coil.