Growth, feeding and thyroxine-related responses of hybrid striped (sunshine) bass (Morone chrysops ♀ X M. saxatilis ♂) fed de-oiled carinata (Brassica carinata) meal

De-oiled (<10 g/kg oil) carinata (Brassica carinata) meal is high (>400 g/kg) in protein, but its use in fish diets will likely be limited mainly by glucosinolates (GLS), sinapine and crude fibre. Two feeding experiments were conducted to determine the response of hybrid striped bass (Morone chrysops female X M. saxatilis male, HSB) to inclusion of cold-pressed carinata meal (CPCM) in diets. Cook extrusion reduced an average of 44% and 57% of GLS and sinapine concentrations in diets, respectively. In experiment 1, diets containing 0.71-2.71 mu moles of GLS and 0.034-0.181 mg of sinapine/g did not significantly (p > .05) reduce feed consumption, utilization or growth, resulting in similar concentrations of thyroxines and consequently no effect on deiodinase enzymes. In experiment 2, there was a significantly reduced (p < .05) feed consumption in fish fed diets containing 5.58-9.52 mu moles of GLS and 0.54-0.75 mg of sinapine/g, resulting in HSB exhibiting lethargic swimming and feeding behaviours, and consequently poor feed utilization and growth. Cook extrusion reduced about half of GLS and sinapine, and HSB tolerated <= 2.71 mu moles of GLS and <= 0.31 mg of sinapine/g of diet without affecting feed consumption and utilization, growth and thyroid metabolism.