A test of the theory that animals seek to eat what they need, is to offer them a choice of two feeds with different protein contents but similar energy yields. The animals, treated in this way, are expected to eat that combination of the two feeds which Just meets their protein and energy requirements. However, in a previous experiment (Kyriazakis, Emmans and Whittemore, 1987), when pigs were offered a choice between two feeds, a high variation in the choices of individuals was observed. This was attributed to the need for an initial learning period, where animals obtain information about the feeds before making “correct choices”. The purpose of this experiment was to compare different ways of giving the opportunity to the animals to learn about the feeds on offer, and to measure their effects on the diets selected by young pigs given choices between the same pair of feeds.