A livestock weighing device that performs a secondary operation such as marking animals having a desired minimum weight with a visual indicia to aid sorting thereof. The weight of an animal moving across the platform actuates a cable system to move a shuttle associated with an actuator. The actuator changes condition to initiate a secondary operation, such as opening an outlet valve for a container of paint to dispense a quantity of paint onto the animal supported on the platform, when the sled is moved in a predetermined direction and the animal weighs more than the minimum required weight.
