To investigate the efficacy of four forms of methionine (Met) supplementation in red swamp crayfish (Procambarus clarkii), a Met-deficient all-plant protein diet was used control, along with four supplemental diets: 0.90 g/kg Met-Met, 1.80 g/kg crystal DL-Met, 3.60 g/kg E-Met, and 3.29 g/kg MHA-Ca. The analysis Met + Cys levels of five diets were 10.46 (control), 11.51, 12.50, 12.56, and 10.70 g/kg, respectively. Each diet was hand-fed to five replicates of 18 crayfish each (initial body weight: 4.40 +/- 0.02 g) for eight weeks. Supplementation with four forms of exogenous Met resulted in an i...
