Effects of dietary n-3HUFA on juvenile white shrimp, Litopenaeus vannamei: Growth, feed utilization, antioxidant enzymes activities and fatty acid compositions

Abstract

Present study investigates the effects of n-3 high-unsaturated fatty acid (n-3HUFA) levels on growth performance, antioxidant enzymes activities and fatty acid compositions of juvenile Litopenaeus vannamei. These represented seven iso-nitrogenous and iso-lipidic diets. Analysed n-3HUFA concentrations were 0.16% (control), 0.48%, 0.74%, 1.39%, 2.39%, 2.92% and 3.44% respectively. A total of 840 juvenile L. vannamei were randomly stocked into 21 0.5 m 3 tanks for 56 days. A significant increase (p < 0.05) was observed from 0.16% to 0.74% n-3HUFA and a decrease when n-3HUFA was above these levels in weight gain rate (WGR) and specific growth rate. Total cholesterol, triglyceride and low-density lipoprotein in serum showed a significant decrease, highdensity lipoprotein showed a significant increase (p < 0.05). Phenoloxidase activity in serum and sodium-potassium adenosine triphosphatase activity in gill were significantly affected by dietary n-3HUFA (p < 0.05), both of them showing a downward trend after upward. Malic dehydrogenase and superoxide dismutase activities in serum were also significantly affected by dietary n-3HUFA (p < 0.05), which rose first and then decreased in general, both of them have a maximum in 2.39% group. No significant differences of the activities of aspartate transaminase and alanine transaminase were observed among all groups (p > 0.05). With dietary n-3HUFA increase, both ∑HUFA and n-3HUFA contents gradually increased in hepatopancreas and tail muscles (p < 0.05). Based on broken-line regression analysis of WGR, the optimal n-3HUFA requirement is 0.89% for juvenile L. vannamei with initial weight of 0.50 ± 0.01 g. K E Y W O R D Santioxidant enzymes activities, fatty acid compositions, growth performance, Litopenaeus vannamei, n-3HUFA

Dietary lipid and n-3 long-chain PUFA levels impact growth performance and lipid metabolism of juvenile mud crab, Scylla paramamosain

“…In the present study, WG and SGR showed at first an increasing and then a decreasing trend with increased dietary n-3 LC-PUFA level regardless of dietary lipid level, and the best growth performance was observed in crabs fed diets containing 19•8 and 13•2 mg/g dietary n-3 LC-PUFA at 7 and 12 % lipid, respectively. The results indicated that excessive dietary n-3 LC-PUFA levels led to detrimental effects on growth performance of S. paramamosain, which was in agreement with previous studies in L. vannamei (4) and Penaeus monodon (29) . A hypothesis put forward to explain this negative effect was the possibility that excessive levels of dietary LC-PUFA, which have higher susceptibility to peroxidation, would result in oxidative stress (30) .…”

“…The result observed in the present study was different to those obtained in P. trituberculatus (initial weight 2•17 and 24•00 g, respectively) (10,11) where the optimum n-3 LC-PUFA requirement was 23•5 and 23•3 mg/g of diet when the dietary lipid was sufficient and DHA:EPA ratios were 0•9 and 1•1, respectively. Different results were also observed in other crustaceans, including Chinese mitten crab (E. sinensis), tiger shrimp (P. monodon), giant freshwater prawn (Macrobrachium rosenbergii) and L. vannamei (4,(33)(34)(35) , which suggested that the optimum n-3 LC-PUFA requirement varies with species, development stages, dietary lipid level, dietary DHA:EPA ratio and feed formulation. On the other hand, the optimal n-3 LC-PUFA level decreased from 20•1 to 12•7 mg/g as dietary lipid level increased from 7 to 12 % in the present study, which showed that .…”

“…Numerous studies have demonstrated that DHA, EPA and arachidonic acid play important roles in survival and growth of marine fish and crustacean larvae (2) , and dietary deficiencies result in reduced survival, poor growth and prolonged intermolt periods of crustaceans (3) . However, it was also reported that excessive dietary LC-PUFA levels could result in growth depression (4) . The EFA must be included in the diet at adequate levels to fulfil requirements for growth, survival and development (5) .…”

“…Other studies showed that the optimum dietary n-3 LC-PUFA requirements for P. trituberculatus (initial weight 2•17 and 24•00 g) were 23•5 and 23•3 mg/g of diet when DHA:EPA ratios were 0•9 and 1•1, respectively (10,11) . The optimal n-3 LC-PUFA requirement was 5•0 and 8•9 mg/g of diet for juvenile Pacific white shrimp (Litopenaeus vannamei) (initial weight 1•43 and 0•50 g) (4,12) , respectively. It was also demonstrated that the optimum n-3 LC-PUFA requirements were higher in subadult than adult L. vannamei (13) .…”

Effects of dietary n‐3HUFA on different growth stages of the white shrimp,Litopenaeus vannamei: Growth, haematological characteristics, enzyme activities and fatty acid profiles

“…The study presented here showed that the variation trend of CHOL and LDL was consisted with the reports mentioned above; however, TG and HDL did not show this similarity. A previous study from our group investigated the effects of dietary n‐3HUFA on serum biochemical indices of juvenile L. vannamei , and the result showed that CHOL, TG and LDL decreased with dietary n‐3HUFA increase, while HDL elevating (Yang et al, ). This discrimination cannot be explained without additional data.…”