Potential of meat meal to replace fish meal in extruded dry diets for barramundi, Lates calcarifer (Bloch). I. Growth performance

Juvenile barramundi (∼220–280 g start weight) were fed extruded dry‐pelleted diets containing varying amounts of fish meal and meat meal in three experiments (E). E1 and E2 were each 66‐day farm studies utilizing 16 floating cages (400 fish per cage) in an aerated freshwater pond. E3 examined the same diets as fed in E2 but under controlled water temperature (28 ± 0.7 °C) and photoperiod (12:12) laboratory conditions in a 42‐day study involving 24 aquaria (eight fish per aquarium). In all studies, the same 430 g kg −1 crude protein (CP), 15 kJ g −1 digestible energy (DE) control (Ctl) diet (containing 35% Chilean anchovy fish meal) was compared with two high‐inclusion meat meal diets and a proprietary diet. The meat meal diets evaluated in E1 were a high‐ash (260 g kg −1 ) meat meal that contained 520 g kg −1 CP and a low‐ash (140 g kg −1 ) meat meal that contained 600 g kg −1 CP when included at either 450 or 400 g kg −1 , respectively, in combination with 100 g kg −1 Chilean fish meal in diets that were isonitrogenous and isoenergetic with the Ctl diet. Growth rates and feed conversions were similar ( P  > 0.05) for all diets. In E2 and E3, the 520 g kg −1 CP meat meal was included at 500 g kg −1 without any marine protein source in diets formulated to provide either 15 or 16.2 kJ g −1 DE and the same CP/DE ratio (29 mg kJ −1 ) as the Ctl diet. Fish performance ranking of diets was similar in both experiments, with the 16.2 kJ g −1 DE diet supporting better ( P  < 0.05) growth rates than the Ctl diet and feed conversion ratios equivalent to the Ctl diet but better ( P  < 0.05) than all other diets.