EFFECT OF FATTY-ACID PROFILE ON DIGESTIBILITY OF DIETARY FATS IN THE INTESTINE OF PIGS

An experiment with 10 castrated male pigs was performed to study the influence on growth characteristics and digestibility of energy (dE) of diets without fat supplementation (K) or supplemented with either extracted fat (EF), pig fat (SF), or two different powder fats (PF1 and PF2) at 10 %. Digestibility of crude fat and fatty acids were determined in three parts of the intestine (ileum, caecum, rectum) at slaughter. The supplemented dietary fats differed in energy content and fatty acid profile. The energy value of EF and SF (39.4 and 39.6 MJ/kg) was higher than that of PF1 and PF2 (37.5 and 35.7 MJ/kg). The relative content of saturated (47, 38, 64, 74 %), monoenic (45, 50, 36, 26 %) and polyenic fatty acids (8, 12, 0.4, 0.8 %) varied between the four dietary fats. Fat supplementation improved average daily weight gain and feed-conversion ratio by up to 16 %. However, no differences were detected between diets supplemented with different fats. The dE was significantly higher in diet SF (0.884) than in the other diets (0.853). The calculated dE of fat SF (0.883) was higher than that of fat EF (0.767), PF1 (0.770) and PF2 (0.749). Chyme analysis showed that crude fat and fatty acids are largely absorbed before the terminal ileum. SF fat had the highest digestibility (0.789) and EF (0.627) had the lowest. Independently of utilized fat, the absorption of oleic and linoleic acid was better than that of stearic acid. Absorption of unsaturated fatty acids was virtually complete. The digestibility of palmitic and stearic acid of PF1 (0.806 and 0.513) and PF2 (0.746 and 0.647) were better than that of EF (0.610 and 0.511) and SF (0.669 and 0.471).