Animals in the concentrate feed system (CFS) presented better feed conversion than animals in pasture feed system (PFS). Animals from CFS took 77 days to reach 35kg whereas animals from PFS took 278 days. The ruminal pH was higher, and more adequate, in the PFS group than the CFS. The CFS lambs presented better quantitative characteristics, conformation and fat deposition. PFS provided leaner and more muscular carcasses in lambs than CFS.