LONG-TERM INFLUENCE OF DIETARY-FAT (SUNFLOWER OIL, OLIVE OIL, LARD AND FISH-OIL) IN THE SERUM FATTY-ACID COMPOSITION AND IN THE DIFFERENT LIPIDIC FRACTIONS, IN MINIATURE SWINE

A total of 24 miniature swine (sus scrofa) was fed with four diets of 9% fat content, differing only in the quality of the fat source (sunfl ower oil, olive oil, lard fat and fish oil) for a 12 months period. Af ter the experimental period, the influence of the dietary fat on the s erum fatty acid composition, and the distribution of those fatty acids in the different serum lipikic fractions was studied. The olive oil g roup had the lowest SI value (total sum of saturated fatty acids) and the highest MUFA value (total sum of monounsaturated fatty acids) in s erum. The sunflower group had higher proportions of n6 polyunsaturated fatty acids in serum, when compared with the remaining groups. The la rd group and the fish oil group had both the highest values of SI and n3 polyunsaturated fatty acids. The results show that fatty acid compo sition in serum reflected, but not in all cases, the fatty acid compos ition of the diet. The highest correspondence was found with sunflower oil and olive oil diets. The existence of interactions between the di fferent fatty acid series was evident, especially with the lard and th e fish oil diets, as well as endogenous synthesis mechanisms. In lipid ic fractions, higher correspondence with diet was found in EC fraction , but, as well as in serum, the existence of interactions between fatt y acid series was evident, and expecially activity and biosynthesis of desaturases may have been affected.