Effect of partially replacing fish meal by poultry by-product meal on growth performance and feed utilization of European eels, Anguilla anguilla (Linné 1758)

A 60-days feeding study was conducted to evaluate the effect of partial substitution (0, 20, 40 and 60%) of dietary fish meal (FM) with poultry by-product meal (PBM) on growth performance and feed utilization ofEuropean elver eels, Anguilla anguilla. A total of 80 A. anguilla with an average initial weight of 1.64 ± 0.13 g were equally divided into the eight glass aquaria (100 L each, duplicate per treatment). All aquaria were filled with well water. Four isonitrogenous (45% CP) and isocaloric 20.0 MJ GE kg^-1 test diets were formulated. A diet containing FM (D₁) as the main source of protein was considered as the control diet. Three tested diets were partially (20 (D₂), 40 (D₃) and 60% (D₄)) substituted for dietary FM protein from control diet with PBM, respectively. In a substitution experiment, the best feed conversion ratio (FCR) and survival rate were obtained with the D₁ (100% FM), while protein effeciency ratio (PER), protein productive value (PPV) and energy retention (ER) were obtained with the D₁ and D₂. The present results indicate that without any significant effect on the PER, PPV and ER, PBM could be used as dietary alternative protein replacement of FM up to the level of 20% for European elver eels, A. anguilla.