Traditional rearing system based on pasture and hay supplementation was compared with rearing systems based on supplementation of barley based concentrate on Tuj lambs. Male Tuj lambs (n = 18) were used in three groups with six lambs in each group. Group T was a control managed as a traditional system with grazing and hay as the main feed sources. In Group TC, lambs were separated from the main flock once a day and offered 500 g concentrate per animal. Lambs in Group C were also separated from the main flock and fed 175 g per day per animal hay and 1 kg per day per animal concentrate. At the end of a 150 days experimental period, lambs were slaughtered and carcasses were evaluated. Liveweights of Groups T, TC and C were 36.4, 38.2 und 41.3 kg, respectively, and cold carcass weights were 17.1, 18.1 and 19.7 kg, respectively (P < 0.05). The results suggest that liveweight and carcass weight can be improved by supplementary feeding of lambs. Economic aspects of concentrate usage were also evaluated. It was concluded that feeding animals with barley based concentrate instead of hay is profitable for breeders. © 2003 Elsevier Science B.V. All rights reserved.