The aim of the paper was to evaluate the quality of muscle tissue of lambs fed with fodder considered as natural for ruminants. Musculus longissimus dorsi samples, taken from two ram groups slaughtered at 25–30 kg of body weight, were the study material. It was found that muscles of lambs fed with pasture green forage, hay and mother’s milk contained less fat and dry matter in relation to other rams fed with the mixture of concentrated fodder, which is important from the dietary point of view. Lamb meat from animals grazing on pasture was characterized with better tastiness as compared to lean from lambs intensively fed using concentrated fodder. It was found that the fodder type was the factor that modified fatty acid profile in lamb meat. Genetic factor played a much smaller role.