Growth, feed efficiency and body mineral composition of juvenile vundu catfish (Heterobranchus longifilis, Valenciennes 1840) in relation to various dietary levels of soybean or cottonseed meals

This study aimed to assess the effect of soybean meal (SBM) and cottonseed meal (CSM), as partial replacement of dietary fish meal on growth, feed efficiency (FE) and body mineral composition of juvenile vundu (Heterobranchus longifilis). Five iso-nitrogenous (390 g kg crude protein) and iso-caloric (18 kJ g, gross energy) diets (Control, SBM30, SBM60, CSM30 and CSM60) were fed to triplicate groups of 40 fish (initial mean weight: 12 g) in each tank (0.9 m). Over a 7-week feeding period, significant differences (P <0.05) were observed on growth, FE and body mineral composition between treatments. Fish-fed CSM-based diets and 600 g kg SBM-based diet had reduced growth and reduced feed and protein efficiencies when compared with those fed diet containing 300 g kg SBM or the control diet. Data from body mineral composition in response to dietary treatment could be divided into two groups. The first group refers to elements such as Mg and Fe for which carcass and fillet composition did not show significant differences with dietary level of SBM or CSM. Ca, P, K, Zn and Mn composed the second group of minerals whose concentrations in fish body were significantly reduced in fish-fed SBM60. In conclusion, the results of this study indicate that although solvent-extracted SBM and CSM are often reported safe for fish, they can only partially replace fish meal as a source of protein in compound feed for vundu at a limited amount between 300 and 600 g kg for SBM and