Investigating the potential effects that long chain polyunsaturated fatty acids have on lipid metabolism in the piglet as a model for the human infant

The objective of the first study was to determine the utilization, safety and efficacy of two sources of LCPUFA, arachidonic acid (AA) and docosahexaenoic acid (DHA). Piglets (n = 10/group) had ad libitum access from day 1 to 16 of age to a skim milk-based formula with different fat sources added to provide 50% of the energy. Treatments included: control with no added LCPUFA (CNTL), single cell oil triglyceride (TG), TG with phospholipid and cholesterol added to match phospholipid content in the PL diet (TG+PL), egg phospholipid (PL), and an essential fatty acid deficient group (EFAD). Formulas with LCPUFA provided 0.6% of fatty acids as AA and 0.3% as DHA. Apparent dry matter digestibility was 10% greater in the CNTL, TG, and TG+PL compared to the PL (P < 0.002). CNTL had 40% longer ileal villi than the PL (P < 0.03), but the TG and TG+PL were similar to CNTL. These data demonstrate that the TG source of AA and DHA may be a more efficacious supplement for infant formulas.; Conjugated linoleic acid (CLA) has been shown to reduce body fat in many species, but little is known about the metabolic interactions between CLA and EFA. Two replicates of 12, 1 d old pigs were fed a milk-based formula ad libitum for 16.5 d that contained 25% (HF) or 3% (LF) fat with either 1% CLA (+CLA) or 1% sunflower oil (−CLA). LF consumed 10% more dry formula than HF (P < 0.05), but 19% less metabolizable energy (P < 0.01). In vitro β-oxidation of 14C-arachidonate, linoleate, and palmitate was not affected by CLA (P > 0.2) or level of dietary fat (P > 0.1) in liver, brain, or muscle tissue. Accumulation of body lipid and protein was reduced by 34% and 14%, respectively in pigs fed supplemental CLA (P < 0.05). These data suggest that CLA in conjunction with a low fat diet reduced body fat while not affecting in vitro oxidation of essential fatty acids.