ABSTRACTCalcium soaps of high oleic sunflower oil (HOS‐Ca) were prepared, using alkaline hydrolysis and calcium precipitation, and freeze‐dried. Cows’ diets were prepared to provide 0, 0.85 kg or 1.7 kg HOS‐Ca/day. Fatty acids and cholesterol were determined by gas chromatography. Sensory evaluations of milk from cows fed 0 and 1.7 kg HOS‐Ca/day were conducted using triangle tests. The 18:lco9 concentration in milk from cows fed the 1.7 kg HOS‐Ca diet increased from 22.9 to 35.2% compared to the control (p<0.05). Concentration of total medium‐chain saturates (C12‐C16) decreased from 40.7 to 31.4% (p<0.05). Feeding HOS‐Ca resulted in increases of monoene fatty acids and lower medium‐chain saturated fatty acids but no ch