This study investigated how feeding systems and acacia foliage supply, a natural tannin source, affect lamb growth, carcass and meat quality. Twenty-eight fat-tailed Barbarine lambs were either grazed or stall-fed, with or without acacia supplementation. Grazing improved growth and carcass yield, while tannins had little impact on meat quality. The results show that the effects of tannins depend on the main diet, highlighting their potential for sustainable lamb production.