Replacement of fish meal by rendered animal protein ingredients in feeds for cuneate drum ( Nibea miichthioides)

Abstract

An 8-week feeding trial was carried out in floating net pens to examine the replacement of fish meal with three rendered animal protein ingredients, poultry by-product meal (PBM), meat and bone meal (MBM) and feather meal (FM) at various levels in practical feeds for cuneate drum. Triplicate groups of fish (initial body weight 27 g fish − 1) were fed nine isonitrogenous and isocaloric feeds formulated to contain 36% digestible protein and 15 MJ kg − 1 digestible energy. The control feed contained 35% herring meal, whereas in the other eight feeds, PBM, MBM and FM, alone or in combination, directly replaced 10%, 30% or 50% of the fish meal. In addition, a raw fish feed was used as a comparison to assess growth performance of fish fed the formulated feeds. There were no significant differences in feed intake and feed conversion ratio (FCR) among fish fed the formulated feeds. Specific growth rate (SGR) and final body weight (FBW) of fish fed the feeds in which either PBM replaced 30% to 50 % of the fish meal or MBM replaced 30% of the fish meal were not significantly different from fish fed the control feed. Feather meal incorporation in the feeds resulted in lower SGR and FBW compared to those of fish fed the control feed. Replacing 50% of the fish meal by MBM significantly lowered SGR, FBW and nitrogen retention efficiency, whereas replacing 50% of the fish meal by a combination of PBM, MBM, FM, blood meal and soybean meal resulted in lower SGR and FBW. There were no significant differences in chemical composition of whole body among fish fed the formulated feeds. Results of the present study indicate that PBM can be used alone at 17% (to replace 50% of the fish meal), and MBM at 10% (to replace 30% of the fish meal) in feeds for cuneate drum.