Effect of dietary phospholipids levels and sources on growth performance, fatty acid composition of the juvenile swimming crab, Portunus trituberculatus

Abstract

An 8-week feeding trial was conducted to investigate the effect of various levels and sources of dietary phospholipids (PL) on growth performance and fatty acid composition of juvenile Portunus trituberculatus. Six semi-purified diets were formulated to contain one control group, three levels of soybean lecithin (SL1%, SL2%, SL4%) and two levels of egg yolk lecithin (EL1%, EL2%), but remaining isolipidtic and isonitrogenous. Each diet was fed in triplicates (18 crabs replicate− 1, initially weighing 22.22 ± 0.08 g). The dietary PL supplementation groups (except the group of SL 2%) had significantly higher weight gain (WG), special growth ratio (SGR) and final body wet weight (FBW) than the control group (P < 0.05). Moreover, crabs fed diets with 2% EL supplementation showed higher SGR than 2% SL supplemented group (P < 0.05). With PL supplementation, we also observed that the highly unsaturated fatty acids (HUFA) percentage of the hepatopancreas and muscle increased with a decrease in the polyunsaturated fatty acid (PUFA) level. Compared with the control group, crabs fed diets with EL supplementation had higher n-3/n-6 ratio in muscle (P < 0.05). Compared with hepatopancreas, higher level of HUFA (especially for C20:5n-3) and lower PUFA level were observed in muscle. Based on growth performance, this study suggested that 1% PL (SL or EL) supplemented in diets could satisfy the requirement of juvenile P. trituberculatus. Moreover, crabs fed diets with EL supplementation had a higher nutritional value of fatty acid profiles than SL groups.