Evaluation of poultry by-product meal in commercial diets for hybrid striped bass (Morone chrysops ♀×M. saxatilis ♂)in recirculated tank production

The efficacy of replacing fishmeal with petfood-grade poultry by-product (PBM) on an ideal protein basis in commercial diets for hybrid striped bass (HSB) was evaluated under production conditions in tank culture. A generic production diet (GEN) for HSB was formulated to contain 45% protein, 12% lipid and 3.7 kcal/kg. Protein in the generic diet was supplied by a mix of animal and plant sources typically used by the industry that included more than 20% select menhaden fishmeal and less than 10% PBM. A positive control diet (GEN+AA) was formulated by supplementing the generic diet with feed-grade Met and Lys to match the level of those amino acids in HSB muscle at 40% digestible protein. Substitution diets were formulated by replacing 35% or 70% of fishmeal in the GEN diet with PBM on a digestible protein basis and then supplementing with Met and Lys (designated 35PBM and 70PBM, respectively) as needed to maintain concentrations of Met and Lys equal to those in the GEN+AA diet. Diet formulation and extrusion were conducted by a commercial mill.