Pedometers are activity meters which are attached to the leg of the cow.
The increased activity of a cow in heat is detected through an increased rate of generation of electrical impulses which are counted and stored in the pedometers circuitry. The pedometer transmits both the activity information stored and the cows identification each time the cow enters the milking parlour. The parlour computer then calculates an average activity level for the previous 10 days. This average value is used for comparison with the current measured values, allowing cow specific deviations to be taken into account. High positive activity deviations from the average value which exceed specified threshold values, indicate heat.