Growth, body composition, and survival of juvenile white bass (Morone chrysops) when dietary fish meal is partially or totally replaced by soybean meal, poultry by-product meal, an all-plant protein blend or a commercial plant-animal protein blend

Abstract

White bass (Morone chrysops) is a popular sportfish throughout the southern United States, and one parent of the commercially successful hybrid striped bass (M. chrysops ♂ x M. saxatilis ♀; HSB). Commercial production of white bass does not currently exist in the U.S. due to a lack of information regarding nutritional requirements and cost-effective diets as well as high production costs. Currently, white bass are cultured using diets formulated for other carnivorous fish that contain a significant percentage of marine fish meal (FM). We evaluated growth, survival, and body composition of white bass fed diets in which FM was replaced by various protein ingredients including soybean meal (SBM), poultry by-product meal (PBM), a combination of SBM, canola meal, and soy protein concentrate, or a commercial protein blend (Pro-Cision™). Six isonitrogenous (40% protein), isolipidic (11%), and isocaloric (17.1 kJ/g) diets were formulated using nutrient availability data for most of the dietary ingredients. Fish (40.2 ± 1.83 g) were stocked into a flow-through (2 L/min) culture system (3 tanks/diet; 10 fish/tank) and fed the test diets twice daily (7 d/wk) to satiation for 60-d. Test diets that replaced FM with various percentages of SBM and PBM resulted in similar performance as fish fed the control diet containing 30% FM. Fish fed the all-plant diet or the diet in which the commercial blend replaced FM resulted in reduced growth performance. Diet performance rankings based on response measures along with differences in essential amino acids and feed intake provided some insight into differences in diet performance. White bass can be fed fish meal-free diets without significantly reducing growth; however, replacement of FM exclusively with plant protein or commercial protein blends may need further study to ensure sufficient intake and performance. Limiting amino acid balance will also need to be addressed in future FM replacement trials with white bass.