A total of 22 pigs (16 castrated males and 6 females) was housed outdoors and fed ad libitum (37-85 kg live weight) on a growing diet and then transferred to an indoor system (with free access to an outdoor area) for 49 days, according to 3 different treatments: 100% concentrate (C), 75% concentrate + ad libitum grass (CE75), 50% concentrate + ad libitum grass (CE50).