Five 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 various weights from 22 to 96 kg. Stepping-into the feeder was more common as feeder depth was increased, but was also dependent upon the size of pig. Grower pigs stepped into a feeder with a depth of 20 cm, but large pigs did not do so until the depth was 30 cm or more. Lip height had only a minor influence of stepping-in. The appropriate feeder depth for each weight group of pig could be approximated by the distance from the toe of the pig to its snout when eating without a feeder lip. The feeder lip restricts access to the front of the feeding zone, particularly for small pigs. Pigs prefer to stand at an angle of approximately 30A?A? to the feed access, but in restrictive feeders will turn their heads to obtain an angled approach. Pigs also rotate their heads approximately 45 – 55A?A? while eating to improve access to the feed.

Ergonomic: is the study of the interaction of animals (or humans) with equipment