Plasma and tissue lipids of piglets fed formula containing saturated fatty acids from medium-chain triglycerides with or without fish oil.

Addition of fish oil (FO) with carbon chain 20 and 22 (long-chain polyunsaturated fatty acids; LCPs) n-3 fatty acids to formula has been considered as a method to provide 22:6n-3 to preterm infants. These studies determined the effects of including 0.73% n-3 LCPs from FO in formula containing saturated fatty acids as medium-chain triglyceride (MCT) oil on plasma and organ triglyceride (TG), phospholipid (PL), and cholesterol ester (CE) contents and compositions in piglets. Reference piglets were fed their own mother's milk. Piglets fed the formula with FO had significantly lower liver and kidney, but not plasma, TG concentrations; lower liver PL 20:4n-6; and higher plasma, liver, and kidney TG, PL, and CEn-3 LCPs than piglets fed the formula without FO. The increase in liver and kidney lipid n-3 LCPs and the decrease in kidney lipid content shows that inclusion of FO in formula with a high content of MCTs and 18:2n-6 does not promote tissue lipid metabolism similar to natural milk feeding. Piglets fed formula with FO had similar brain 20:4n-6 and 20:5n-3 but higher 22:6n-3 than did piglets fed sow milk. Diet-related differences in plasma and red blood cell PL were not reliable predictors of differences in brain LCP.