A feeder for pigs includes a hopper and a trough for receiving the feed where an elongate opening is defined by an elongate shelf to control the amount of feed discharged from the hopper to the trough. An adjustment linkage for lifting the shelf against the weight of feed in the hopper includes a first lift screw and a second lift screw each for applying a lifting force to the elongate adjustment member located at spaced positions from the end walls of the hopper. Each of the screws includes a gear box with a shaft connected between the two gear boxes to communicate drive therebetween for simultaneous operation of the lift screws by a hand crank connected to one at the top of the feed in the hopper.