The aims with the project were to investigate how forage consumption affect production and pigs behaviour around the feeding. This degree project was designed to follow 48 growing/finishing Hampshire*Yorkshire pigs, from 30-110 kg live weight, fed diets with or without 20 % forage inclusion. The pigs were divided in three groups due to dietary treatment. In the first group the pigs were fed 20 % of the energy in the feed ration by long grass/clover silage (LE) and the remaining 80 % by a cereal concentrate. Group two was fed chopped grass/clover silage mixed with cereal concentrate (HE) in the same amounts as LE. The third group was the control group (K), fed 100 % of the cereal concentrate alone. The different groups were compared regarding growth rate, carcass quality and behaviour. The pigs were weighed once a week throughout the study period and the day before slaughter. Their behaviour around feeding was recorded four times during the growing/finishing period, at the age of 3.5-5.7 month. The pigs were fed twice a day. Both HE and LE left some of the grass/clover forage, after chewing it which was collected before the next feeding event. The nutritive content in the silage samples taken before and after the pigs had chewed was compared. Both slaughter weight and meat percentages were accomplished in the slaughterhouse. The grass clover silage had an estimated metabolizable energy (ME) content of 9.1 MJ/kg dry matter and a fibre content of 46.1 %. In the chewed silage the calculated ME content was 6.4 MJ/kg dry matter and the fibre content was 65.7 %. HE and LE had a lower growth rate than K (p=0.001). The average weight before slaughter in HE and LE was 105 kg and 112 kg in K. The proportion of lean meat in the carcass was 58.8 % in LE and corresponding figures for K was 57.7 % (p=0.036). The major part of social interactions was performed before the feeding and both aggressive and non-aggressive interactions were performed more often in K then in both HE and LE (p=0.001). The occurrence of social interactions increased with age of the pigs (p=0.05).