AbstractBeef production with Holstein male calves is becoming more intensive in Uruguay. Some of the new systems with confined animals could improve productivity but also could compromise animal welfare. The aim of this study was to compare animal welfare, stress evidence and productivity of castrated young males reared in three differentproductive systems. The traditional pastoral system (T3) was compared with, a confined fattening system (T1) and an alternative one with confinement and six hours diary access to pastures (T2). The experiment was performed for evaluating the first phase of fattening period (initial mean live weight 93±20.3 kg; and 112±11 days of age). Nodifferences (p = 0.1254) between treatments were detected for live weight gain 0.756±0.829, 0.757±0.676 and 0.730±0.762 kg day-1 for T1, T2 and T3, respectively. There was no evidences of increasing stress or health problems in any production system, according to the obtained serum profile of enzymes and hormones, howeverpermanent confined animals increased agonistic behavior, which could reflect some welfare problems that might increase in the following phases of the fattening process. © Canadian Center of Science and Education