Regulation of dietary phospholipids on growth performance, antioxidant activities, phospholipid metabolism and vitellogenesis in prereproductive phase of female swimming crabs, Portunus trituberculatus

Abstract

Sixteen weeks feeding trial was conducted to evaluate the effects of dietary phospholipid (PL) supplementation on growth performance, antioxidant activities, phospholipid metabolism key enzyme activities, and vitellogenesis in prereproductive phase of female P. trituberculatus. Six diets were formulated to contain 0.99%, 1.65%, 2.51%, 3.63%, 4.95% or 6.12% phospholipid, respectively. Crabs with an initial body weight of 25.48 ± 0.12 g were divided into six treatments, each diet was randomly assigned to feed sixty female swimming crabs. The results indicated that final body weight (FBW), weight gain (WG) and specific growth rate (SGR) were significantly influenced by dietary PL levels, and the highest WG and SGR were observed at crab fed the 3.63% PL diet. Crabs fed the 6.12% PL diet had lower n-6 PUFA contents in hepatopancreas than those fed the other diets, however, crabs fed the 4.95% and 6.12% PL diets had the highest DHA, n-3 PUFA in hepatopancreas among all treatments. Moreover, dietary PL levels significantly affected catalase, reductive glutathione, superoxide dismutase activities, phospholipid transporter, phosphocholine cytidine transferase, phospholipase A2, and fatty acid synthase activities in hepatopancreas. Crabs fed the 4.95% PL diet had the highest total antioxidant capacity in hepatopancreas. The hepatopancreatic malondialdehyde concentration significantly increased with the dietary PL levels increasing from 0.99% to 6.12%. Vitellogenin mRNA expression were up-regulated in hepatopancreas and ovaries as the dietary PL levels increased, and 17 β-estradiol (E2) and progesterone (PROG) contents in hepatopancreas, serum and ovaries were similar trend. The results of present study demonstrated that optimum dietary PL could enhance growth performance, improve the activities of antioxidant and lipid metabolic enzymes in hepatopancreas, and regulate vitellogenesis in prereproductive phase of female P. trituberculatus by regulating the synthesis of E2 and PROG.