Replacement of fish oil withSchizochytriummeal and its impacts on the growth and lipid metabolism of Pacific white shrimp (Litopenaeus vannamei)

Abstract

A 12‐week experiment was conducted to evaluate replacing fish oil (FO) in Pacific white shrimp (Litopenaeus vannamei) diets with algal meal (Schizochytrium sp. [AM]) and vegetable oils (VO: linseed oil [L] and soybean oil [S]). For this purpose, 15 aquaria (110‐L each) were arranged in an indoor rack recirculating saltwater system (salinity, 27–28 ppt) and a 2,000‐L mechanical and biological propeller‐washed bead filtration system. Juvenile shrimp (initial weight, 3.15 ± 0.01 g) were randomized into five groups of three replicates and fed one of five iso‐nitrogenous (400 g/kg crude protein) and iso‐lipidic (100 g/kg lipid) diets such as control (50 g/kg FO), FO‐AM0 (80 g/kg FO), FS‐AM1 (40 g/kg FO + 20 g/kg VO + 28.8 g/kg AM), FLS‐AM2 (20 g/kg FO + 20 g/kg VO + 58.7 g/kg AM) and LS‐AM3 (0 FO + 20 g/kg VO + 88.5 g/kg AM). No differences were found in most production performance parameters, except final body weight, which was significantly (p < 0.05) lower in the group fed diet LS‐AM3 (complete replacement of fish oil) compared with those fed diets FO‐AM0 and FLS‐AM2. Proximate and fatty acids composition were altered by the supplementation of AM and VO. Muscle and hepatopancreatic linoleic acid, linolenic acid and docosahexaenoic acid levels increased with increasing dietary AM, while eicosapentaenoic acid levels decreased. AM and VO supplementation significantly influenced the major total fatty acids in the tail muscle (MUFA, n‐6 PUFA, n‐3 PUFA and LC‐PUFA) and hepatopancreas (SFA, MUFA, LC‐PUFA and ratio of n‐3/n‐6), with higher n‐6, n‐3 and LC‐PUFAs and ratios of n‐3/n‐6 in high AM diets (LS‐AM3 and FLS‐AM2). Lipase activity increased with increasing dietary AM, whereas adipocytes decreased (p < 0.05). Significantly lower total cholesterol was measured in groups fed control and FLS‐AM2 diets compared to those fed FO‐AM0 and LS‐AM3. Algal meal could replace FO up to 75% and play an important role as a source of essential fatty acids in shrimp diets without compromising growth and health.

Effect of different stock types and dietary protein levels on key enzyme activities of glycolysis‐gluconeogenesis, the pentose phosphate pathway and amino acid metabolism inMacrobrachiumrosenbergii

“…The current experimental trial to evaluate the effect of diet protein level and the effect of stock strain of freshwater prawn has yielded some interesting findings. A significantly higher hepatopancreatic to osmotic changes was shown in Neohelice granulata (Kumar et al, 2018;Martins et al, 2011). Therefore, gills demonstrate con- suggesting that more conducive water conditions of M. rosenbergii farm were encountered for this experiment than the influence on feed or stock mediated variations.…”

“…Fish or shrimp gills are influenced more by osmotic changes than by dietary conditions alone. Change in gills FBPase activity in response to osmotic changes was shown in Neohelice granulata (Kumar et al, ; Martins et al, ). Therefore, gills demonstrate consistent FBPase activity across all experimental groups in this study suggesting that more conducive water conditions of M. rosenbergii farm were encountered for this experiment than the influence on feed or stock mediated variations .…”

“…However, commercial and/or wild stock of M. rosenbergii has been sharply declining all around the globe during the last two decades. Therefore priorities must be directed toward an approach to identify optimum stocks in a given culture condition (Bowyer et al, ; Davies, Gouveia, Laporte, Woodgate, & El‐Haroun, ; El‐Husseiny, Hassan, El‐Haroun, & Suloma, ; Goda et al, , ; Hassan et al, ; Hassaan, Mahmoud, et al, ; Hassaan, Soltan, et al, ; Kumar et al, ; Sagar et al, ). The growth performance of prawns is influenced by various factors such as water, soil quality, stocking density, sex ratio, feeding methods, and feed types.…”

Effects of dietary Nannochloropsis sp. powder and lipids on the growth performance and fatty acid composition of larval and postlarval kuruma shrimp, Marsupenaeus japonicus

“…and other thraustochytrids, as prominent and sustainable sources of oils rich in long‐chain n‐3 polyunsaturated fatty acids (n‐3 LC‐PUFA) and high level of total lipids. Kumar et al () replaced at levels up to three quarters fish oil with Schizochytrium sp. meal, linseed oil and soybean oil in L. vannamei diets.…”

Effects of dietary fish oil replacement with blended vegetable oils on growth, lipid metabolism and antioxidant capacity of subadult swimming crabPortunus trituberculatus

“…Therefore, dietary fish oil replacement by vegetable oils may change the balance of fatty acid compositions and affect the growth and development of aquatic animals (Li et al, , ; Mu et al, ). Previous studies showed that dietary fish oil replacement with vegetable oils could affect the lipid metabolism of fish, shrimps and crabs (Castro, Corraze, Panserat, & Oliva‐Teles, ; Kumar et al, ; Peng et al, ; Zhao, Long, Wu, Liu, He, et al, ). Meanwhile, dietary fish oil replacement by vegetable oil may also affect the antioxidant capacity and health status of aquatic animals, which could be understood according to the antioxidant indices (Peng, Li, Lin, & Chen, ; Zhang, Li, Liao, Ye, & Wang, ).…”