A weigh scale and a sorter unit mounted at a front gate for guiding the animal after weighing when the animal emerges from the front gate is transported from pen to pen within a barn on ground wheels with the sorter unit being mounted so as to be movable from a deployed position to a retracted transport position by folding or sliding, in which a total length of the weigh scale and sorter unit is reduced relative to a total length thereof in the deployed position for maneuvering the weigh scale with sorter unit attached during transportation.