5 ergonomic studies were conducted using a feeder on which the lip height, feeder depth (front to back), width and feeding shelf height could be adjusted. Pigs were tested at 22 to 96 kgs. Stepping into the the feeder was more common as feeder depth was increased, but was dependent on the size of the pig. Grower pigs stepped into a feeder with a depth of 20 cm, but large pigs didn’t step into the feeder until the depth was 30 cm or more. Lip height only had a minor influence on stepping-in. The appropriate feeder depth for each weight group of pig could be approximated by the distance from the toe of a pig to its snout without a feeder lip. The feeder lip restricts access to the front feeding zone, particularly for small pigs. Pigs prefer to stand at an angle of 30degrees to the feed access, but in restrictive feeders will turn their heads to obtain the an angled approach. Pigs also rotate their heads 45-55 degrees while eating to improve access to feed.