Environmental enrichment can be defined as an increase of the biological relevance of captive environments by appropriate modifications resulting in an improvement of the biological functioning of captive animals (Newberry, 1995). In general, enrichment should present objects or situations to act with a rewarding outcome. In applied ethology improved animal welfare and health as well as an adequate coping with stress are major indicators for assessing the relationship between farm animals and their housing environment. Animals interpret their interactions with the environment in an emotional way on the basis of present and previous experience (Wiepkema and Koolhaas, 1992). This will be the case especially if an animal can expect a rewarding result (Spruijt et al., 2001). Up to now, the development of cognitive tasks to study emotional or hedonic states in animals is rather rare and predominantly restricted to laboratory animals (e.g. Harding et al., 2004; Van der Harst et al., 2005). Therefore, there is an urgent need for increasing experimental research on this field, which should necessarily include farm animals. For this purpose we have recently developed a food-rewarded learning system for pigs using acoustic cues in a combination of classical and operant conditioning techniques (Ernst et al., 2005). The purpose of the present paper was to verify that automated feeding by offering cognitive challenges is functioning reliably and does not impair weight development in replicated trials with pig groups, as should be expected by a successful learning behaviour. However, the main goal was to investigate the effects of a sustained cognitive enrichment on the general behavioural reactivity of domestic pigs. The present study investigated the characteristics of learning behaviour in seven experimental groups (n = 8 individuals each) of growing pigs in postnatal weeks 7–20. The behavioural budget of each group was observed weekly within the housing environment and compared to seven conventionally fed control groups (n = 8), which were supplied with an equal food amount. The alterations of individual behavioural responses after 6 and 12 weeks of cognitive enrichment were analysed in combined open-field/novel-object tests and compared to controls. All experimental pigs were able to discriminate reliably an individual tone that was associated with a locally changing feeding site. Generally, the animals were also willing to work for food (push a button) but this motivation varied considerably between the groups ranging from FR 1 to 10. Sustained cognitive enrichment also affected other behavioural patterns within the housing environment as indicated by an increased locomotor behaviour and less belly nosing. Behavioural test responses were altered towards a greater reduction in open-field activity as well as a reduced excitement and fear behaviour compared to control pigs. Behavioural differences seem to be more pronounced the longer pigs were faced with the cognitive challenge. However, with equal food intake, the weight gain of the experimental pigs was not different compared to the controls. The present study suggests that, in domestic pigs, the presented cognitive enrichment may induce repeated positive appraisals in pigs by the association of successful coping with a demanding behavioural task rewarded by several small portions of food during the day. This appears to agree very well with pigs’ motivational needs and may also be applicable for animal welfare enhancing management of feeding.