ABSTRACT
This chapter focuses on nutrient availability data for the various freshwater fishes, maximum levels of incorporation, supplementary nutrients needed in high soybean diets, and the known effects of antinutritional factors. Soybean seeds and resulting meals from those seeds have become an important source of crude protein and essential amino acids (EAA) in diets fed to freshwater fishes. Use of soy products requires supplementation with other macro- and micronutrients, such as lipid, inorganic P and EAA in some species, but it is clear that soy has become the focus of research efforts in fish diets. There are numerous soybean feedstuffs available for use in diets and most have been evaluated. Soybean protein is considered a high-quality plant protein source in diets fed to freshwater fish, but contains lower concentrations of methionine, lysine, and threonine compared to fish meal. Thus, protein quality is generally thought to be inferior to fish meal.
