The aim of this study was to compare the effects of grazing tetraploid triticale (DDRR genome) as a pure crop (TMC) or in association with crimson clover (TAINC) on the production, chemical composition and fatty acid profile of milk in Holstein‑Friesian cows supplemented with maize silage and concentrate. Twelve cows were distributed among two groups and each group was assigned to a grazing plot for two nine‑day periods. Fat and total‑solids corrected milk (FCM and FCMs) yield and composition did not differ among grazing plots. Proportions of both omega 3 and 6 fatty acids were similar in both treatments (P>0.05) while rumenic acid was greater in TAINC (1.29 g 100 g^‑1 of fatty acids) than in TMC (0.87 g 100 g^‑1 of fatty acids)(P<0.05). The contents of unsaturated and mono‑unsaturated fatty acids in the milk were also comparable in the two grazing treatments, while poly‑unsaturated fatty acids were higher (P<0.05) in TAINC.