Grape seed oil was isomerized on CaO in (HOCH2)(2) to Ca conjugated linolate (5.6%), while a fish oil was low-temp. crystd. to increase content of eicosapentaenoic and docosahexaenoic acids to 41.5%. Both prepns. were supported on a corn. humus-mineral sorbent and used as a supplement cows diet at 400 g/head/day to modify the fatty acid profile of milk fat. The share of conjugated dienes of cis-9, trans-10 and trans-10, cis-12 linoleic acids C18:2 in milk fat increased by 55-150% and trans-11 vaccenic acid C18:1 by 62-110% as a result of the diet improvement. Transfer of the fatty acids profile from milk to rennet cheese was also confirmed.