This study evaluated the effect of flax meal (FM) and barley rootlets (BR) in Holstein dairy cows compound feeds (CFs) in order to assess their effects on the quality (physico-chemical parameters and fatty acids composition) and quantity (yield) of raw milk. The trial used a number of 15 multiparous Holstein dairy cows, at 27 weeks midlactation stage, averaging 624.19 kg of BW, with an initial average milk yield of 22.36 litres/day. The cows were divided in 3 groups (C, FM and FMBR diet, respectively), for 63 days. Cows were fed twice/day, and received a basic concentrate mix (corn, soybean meal, sunflower meal and wheat bran) and roughage (alfalfa hay and corn silage). The use of FM in dairy cows' CFs resulted significant increase of milk fatty acids (FA) and milk yield. At the end of the trial for both experimental groups (FM and FMBR), the C18: 3n3 FA was significantly higher, (0.526% and 0.522% vs. 0.23% C group of total FAMEs), representing a good source of n3. This indicates that the fatty acid addition from FM was favourable to the C18: 3n3 fatty acid in milk.