A silo content monitoring system for a silo, the silo comprising: a shell; a hopper; an outlet aperture located at or towards the base of the hopper; a discharge tube connected to the outlet aperture; a rotatable auger located within the discharge tube; and a plurality of support struts for supporting the shell, hopper, and outlet aperture above ground level, the silo content monitoring system being characterised by: a strain gauge affixed to at least one of the support struts; a motion sensor adapted to detect rotation of the auger relative to the discharge tube; and central processing unit comprising: a calculating means; a real-time clock; an input/output interface connected to the strain gauge, the motion sensor and to a read-out device, wherein the central processing unit is adapted, in use, to: during a nighttime interval, to monitor an output of the strain gauge to ascertain an overall weight of the silo, subtract a tare weight from the overall weight to obtain an overnight silo content weight measurement during a daytime interval, to monitor an output of the motion sensor and for each rotation or part-rotation of the auger, calculate an estimated dispensed weight; and to output, via the read-out device, a subtractive silo content weight estimate being the overnight silo content weight measurement, minus the estimated dispensed weight. the silo comprising: a shell; a hopper; an outlet aperture located at or towards the base of the hopper; a discharge tube connected to the outlet aperture; a rotatable auger located within the discharge tube; and a plurality of support struts for supporting the shell, hopper, and outlet aperture above ground level, the silo content monitoring system being characterised by: a strain gauge affixed to at least one of the support struts; a motion sensor adapted to detect rotation of the auger relative to the discharge tube; and central processing unit comprising: a calculating means; a real-time clock; an input/output interface connected to the strain gauge, the motion sensor and to a read-out device, wherein the central processing unit is adapted, in use, to: during a nighttime interval, to monitor an output of the strain gauge to ascertain an overall weight of the silo, subtract a tare weight from the overall weight to obtain an overnight silo content weight measurement during a daytime interval, to monitor an output of the motion sensor and for each rotation or part-rotation of the auger, calculate an estimated dispensed weight; and to output, via the read-out device, a subtractive silo content weight estimate being the overnight silo content weight measurement, minus the estimated dispensed weight. a strain gauge affixed to at least one of the support struts; a motion sensor adapted to detect rotation of the auger relative to the discharge tube; and central processing unit comprising: a calculating means; a real-time clock; an input/output interface connected to the strain gauge, the motion sensor and to a read-out device, wherein the central processing unit is adapted, in use, to: during a nighttime interval, to monitor an output of the strain gauge to ascertain an overall weight of the silo, subtract a tare weight from the overall weight to obtain an overnight silo content weight measurement during a daytime interval, to monitor an output of the motion sensor and for each rotation or part-rotation of the auger, calculate an estimated dispensed weight; and to output, via the read-out device, a subtractive silo content weight estimate being the overnight silo content weight measurement, minus the estimated dispensed weight. during a nighttime interval, to monitor an output of the strain gauge to ascertain an overall weight of the silo, subtract a tare weight from the overall weight to obtain an overnight silo content weight measurement during a daytime interval, to monitor an output of the motion sensor and for each rotation or part-rotation of the auger, calculate an estimated dispensed weight; and to output, via the read-out device, a subtractive silo content weight estimate being the overnight silo content weight measurement, minus the estimated dispensed weight.