Effect of Dietary Phospholipids on Digestion of Neutral Lipid by the Prawn Penaeus monodon

Abstract— Different amounts of dietary phospholipid were tested for their effect on the digestibility of total neutral lipids in the diet of the prawn Penaeus monodon . A purified source of the phospholipid, L-α-phosphatidylcholine, was included at 0. 5, 10, 20 or 40 g/kg in a purified diet containing 80 g/kg olive oil as the predominant neutral lipid source. The apparent digestibility of the neutral lipid (ADNL) in these diets was determined by comparing concentrations of the digestibility marker, cholestane in the feed and faeces of the prawns. ADNL (%) increased curvilinearly with increasing dietary phospholipid content (X, %) as described by the equation: ADNL = 80.4 + 9.08X -1.705X² (P < 0.05; R² = 0.71); the asymptote of 92.5% was achieved with a phosphatidylcholine value of 27 g/kg. These results demonstrate that phosphatidylcholine significantly increases the digestibility of neutral lipids by penaeid prawns. However, olive oil was used as the predominant neutral lipid source to examine the effects with a relatively poorly digestible lipid source. The effects of phosphatidylcholine on more readily digested lipid sources such as fish oils, may not be as great, but still be sufficient to improve the utilisation of these nutrients.