Predicting the optimal dietary essential amino acid profile for growth of juvenile yellow perch with whole body amino acid concentrations

Rapid methods of estimating dietary essential amino acid (EAA) requirements might facilitate increases in aquaculture production, particularly for new or emerging industries. We conducted a 12-week feeding study to test the hypothesis that whole body EAA concentrations and the quantified methionine requirement could be used to predict the remaining dietary EAA requirements for juvenile all-female yellow perch. Six purified diets were developed and fed to triplicate groups of fish for 12 weeks. The diets contained the EAA profile of fishmeal (FM), the profile as predicted by whole body analysis, the quantified methionine requirement and resulting A/E ratios (PRED), PRED + 20% of all EAA (PRED20), PRED + 40% of all EAA (PRED40), PRED + 20% threonine, isoleucine and tryptophan (PRED320), and PRED + 40% threonine, isoleucine and typtophan (PRED340). Mean weight gain and feed consumption were significantly higher in fish fed PRED20 (35.7 +/- 3.2 and 55.0 +/- 5.3 g, respectively) than in fish fed FSM (25.1 +/- 0.4 g wt gain, 41.0 +/- 1.9 g cons), PRED (23.4 +/- 2.3 g wt gain, 40.1 +/- 4.2 g cons) and PRED340 (22.9 +/- 3.3 g wt gain, 35.0 +/- 3.8 g cons). There was no significant difference in feed efficiency among treatments. We recommend an EAA profile similar to PRED20 for feeding all-female juvenile yellow perch.