Optimal dietary linoleic acid to linolenic acid ratio improved fatty acid profile of the juvenile tambaqui ( Colossoma macropomum )

Abstract

The present study aimed to evaluate the effect of dietary linoleic acid to linolenic acid (LNA/ALA) ratio on growth performance, feed utilization, plasma metabolite profiles, and muscle and liver fatty acid profiles of juvenile tambaqui Colossoma macropomum. Six diets were formulated to contain incremental levels of corn oil (rich in LNA) from 0 to 7% at the expense of linseed oil (rich in ALA), resulting in dietary LNA/ALA ratios ranging from 3.1 to 26.9. A control diet including fish oil was also formulated. The trial lasted 49 days, and each diet was assigned to six groups of fish with an initial body weight of 43 g. At the end of the trial, dietary LNA/ ALA ratio did not affect growth performance, feed utilization, and plasma metabolites profile, except for HDL that was lower in fish fed the 3.8 LNA/ALA diet than the 3.1 or 5.0 LNA/ALA diets. Whole-body protein content was lower in fish fed the control and 3.1 LNA/ALA diets. Composition of triglycerides, glucose and protein of liver and muscle was unaffected by dietary treatments. Eicosapentaeneoic acid (EPA, 20:5n-3) plus docosahexaenoic acid, (DHA, 22:6n-3) content of muscle decreased with the increase of LNA/ALA ratio. Fish fed 3.9-5.6 LNA/ALA diet showed the highest concentration of muscle ARA (arachidonic acid, 20:4n-6) and EPA + DHA among vegetable oil diets, though lower than that of fish fed the fish oil based diet. In conclusion, dietary LNA/ALA ratio should range between 3.9-5.6 to produce fillets with high EPA, DHA, and ARA contents, thus improving the nutritional quality of tambaqui fillets for human consumers.

A complete enzymatic capacity for long-chain polyunsaturated fatty acid biosynthesis is present in the Amazonian teleost tambaqui, Colossoma macropomum

“…The essential FA for a given species depends upon its desaturation and elongation capability to endogenously convert dietary C18 PUFA LA and ALA into the biologically active LC-PUFA, namely ARA, EPA and DHA (Tocher, 2015). Recent investigations have shown that tambaqui juveniles exhibited no difference in growth performance when fed diets containing mixtures of VO (corn and linseed oils) in comparison to fish fed a fish oil (control) diet (Pereira et al, 2017;Paulino et al, 2018). Consequently it was established that tambaqui can fulfil its essential FA requirements with dietary provision C18 PUFA (Paulino et al, 2018).…”

“…Recent investigations have shown that tambaqui juveniles exhibited no difference in growth performance when fed diets containing mixtures of VO (corn and linseed oils) in comparison to fish fed a fish oil (control) diet (Pereira et al, 2017;Paulino et al, 2018). Consequently it was established that tambaqui can fulfil its essential FA requirements with dietary provision C18 PUFA (Paulino et al, 2018). The present study provides compelling molecular evidence that support previous findings and unequivocally demonstrates that all the desaturase and elongase activities required to convert C18 PUFA into ARA, EPA and DHA exist in tambaqui within the three genes studied herein, i.e.…”

Dietary lipid level and source affect metabolic responses in hybrid catfish (Pseudoplatystoma reticulatum × Leiarius marmoratus)

“…As expected, both liver and muscle n3/ n6 ratios were higher in fish fed the FO than the VO diets. VO, principally those rich in n6, as corn and soya bean oil, greatly reduced n3/n6 fatty acid ratio and increased deposition of C18:2n6 in muscle and liver of fish (Lima et al, 2019;Monge-Ortiz et al, 2018;Paulino et al, 2018;Piedecausa, Mazon, Garcia, & Hernandez, 2007;Regost, Arzel, Cardinal, Rosenlund, & Kaushik, 2003).…”

“…PUFA can be converted to longer chain, more unsaturated and physiologically important long‐chain (LC) PUFAs by freshwater fish (Henderson & Tocher, ; Sargent, Bell, Bell, Henderson, & Tocher, ). However, species‐related differences in desaturation or elongation capacity exist (Hastings et al, ; Zheng et al, ) and the extension of bioconversion of PUFA into LC‐PUFA may be modulated by the dietary fatty acid profile (Paulino et al, ).…”

Protein‐sparing effect by dietary lipid increase in juveniles of the hybrid fish tambatinga (♀ Colossoma macropomum × ♂ Piaractus brachypomus )

“…Serrasalmidae fish of the genera Colossoma and Piaractus include some of the most important omnivorous species for aquaculture in Latin America (Guimarães & Martins, ). As a result, studies on nutritional requirements on species of Colossoma and Piaractus have significantly grown in recent years (Garcia, Gutiérrez‐Espinosa, Wásquez‐Torres, & Baldisserotto, ; Guimarães & Martins, ; Lima, Bomfim, Siqueira, Ribeiro, & Lanna, ; Nascimento Filho et al, ; Paulino et al, ). On the other hand, although interspecific hybrids of those species accounted for 39% of the 483,241 t of fish produced by Brazilian aquaculture in 2015 (IBGE, ), nutritional studies on these fish are scarce (Pereira, Azevedo, & Braga, ; Uzcátegui‐Varela, Méndez, Isea, & Parra, ).…”