Two groups of 6 ewes, each suckling a single ram lamb, were fed diets with 73% forage and 27% concentrate. In the experimental group, part of the concentrate was replaced by 100 g rapeseed and 50 g linseed. Lambs were slaughtered at 70 days of age (body weight about 22 kg) and their leg muscles, M. adductor and M. semitendinosus were taken for estimation of chemical composition and fatty acid profle. It was found that the rapeseed and linseed supplement had a benefcial effect on the fatty acid profle, especially CLA, and increased the content of fat in milk. The change in milk composition influenced the quality of lamb meat only to a small extent. A reduced content of intramuscular fat and increased proportion of n-3 PUFA were found.