ABSTRACT.- Ninety lambs reared on pastures were slaughtered for 2 y corresponding to 3 ages of slaughter:At weaning with 4 mo of age (4M), at 6-7 mo of age (6M), and at 12 mo of age (12M; last treatments were weaned at 4 mo). With the purpose of deseasonalizing high-quality meat lamb production in the year, the present work aimed to achieve hot carcass weight (HCW) of 18?20 kg on average in each lamb group. Hot carcass weight, carcass yield (CYd), subcutaneous tissue depth, leg, frenched rack, and loin weights were determined. After meat ageing for 7 and 14 d from the 3 groups of lambs, instrumental color, Warner-Bratzler shear force (WBSF), consumer sensory analysis (n = 200), and fatty acid profile of intra muscular fat (IMF) were determined on longissimus lumborum muscle. Lambs of 12M resulted in greater HCW (P