| Abstract: | Soybean meal (SBM), corn gluten meal (CGM), and canola protein concentrate (CPC) as alternative protein sources to fish meal (FM) were individually evaluated for growth performance at 0, 20, 30, 40, and 50% replacement with amino acid (AA) supplementation using juvenile summer flounder, Paralichthys dentatus, in an 8‐wk feeding. Two‐way ANOVA indicated no significant main effect for plant protein source, but a significant main effect for replacement level. Comparison of the individual treatments revealed significant differences in weight gain (WG) between the FM treatment and 50% replacement level for all protein sources, as well as between the FM treatment and 30% replacement with CPC. Replacement of FM with SBM at 40% resulted in the least cost/kg WG. In a follow‐up study, a combination of SBM–CGM–CPC at 40% replacement was evaluated with and without AA, phytase (0.2%), or taurine (1%), versus FM and SBM (40% replacement of FM) with AA. The SBM–CGM–CPC diet with either AA or taurine provided a significantly better food conversion ratio and less cost/kg WG than the SBM diet, and the SBM–CGM–CPC diet with taurine provided a significantly better protein efficiency ratio than the SBM diet. On the basis of these results, more study of taurine in plant protein diets for summer flounder appears warranted. |
