Optimal dietary lysine improves growth performance, increases protein deposition and reduces lipid accumulation in tambaqui (Colossoma macropomum) juveniles

• Published in: Aquaculture research Vol. 51; no. 12; pp. 5065 - 5073
• Main Authors: Teixeira, Samuel Oliveira, Nunes, Zélia Maria Pimentel, Junior, Arlindo dos Santos Pinheiro, Salaro, Ana Lucia, Moura, Lorena Batista, Veras, Galileu Crovatto, Campelo, Daniel Abreu Vasconcelos
• Format: Journal Article
• Language: English
• Published: Oxford Hindawi Limited 01.12.2020
• Subjects: Amazonian fish; amino acid; Aquariums; Body composition; Body weight gain; broken‐line model; Colossoma macropomum; Conversion ratio; Deposition; Diet; Feed conversion; Feeding experiments; Fish; Food conversion; Growth rate; Hematology; Juveniles; Lipids; Lysine; Metabolites; Minors; Optimization; Physical growth; Polynomials; Proteins; Regression analysis; Variance analysis; Weight gain; whole‐body composition
• ISSN: 1355-557X; 1365-2109
• DOI: 10.1111/are.14845

The present study aimed to determine the dietary lysine requirement for tambaqui (Colossoma macropomum) juveniles, based on growth performance, whole‐body composition, haematological parameters and plasma metabolites. For that purpose, an 81‐day feeding trial was conducted with 150 tambaquis distributed in 15 aquariums (300 L) in a completely randomized design, with five treatments and three replicates. Five diets were formulated and crystalline l‐lysine was added to obtain diets with lysine concentrations of 9.1; 11.9; 14.7; 17.5; and 20.3 g/kg dry diet. Data were subjected to one‐way analysis of variance (p < .05), analyses of broken‐line and second‐degree polynomial regressions were combined to determine dietary lysine requirement. Fish fed 14.9 to 21.0 g/kg lysine showed higher weight gain, specific growth rate and lower feed conversion ratio, viscerosomatic index. In addition, dietary lysine levels of 15.6 and 19.4 g/kg provided higher fish whole‐body deposition of protein and lower deposition of lipid respectively. There were no significant differences in haematological analysis and plasma metabolites of the fish. Thus, according to the second‐order polynomial analysis of a broken‐line response for weight gain, the optimum dietary lysine requirement for tambaqui juvenile was estimated to be 16.1 g/kg dry diet (5.4% dietary protein).