The preferred embodiment of the present invention is a folding feed device adapted to mount to a horse trailer. The device includes a vertical frame member configured to couple to a sidewall of the horse trailer and a hingeable bottom (or horizontal) frame and feeding tray assembly whereby the feeding tray is operable from a first vertical closed position to a second, horizontal open position. The feeding tray is a substantially flat, planar surface. At least one support chain links from an outer edge of the feeding tray to a position on the intermediate horizontal truss whereby in the first closed position the chain is loose and fits between the feeding tray and the vertical frame member and in the second, horizontal open position the chain is taught and configured to retain the feeding tray in the horizontal position.
