Relative use of dietary carbohydrate, non-essential amino acids, and lipids for energy by hybrid striped bass, Morone chrysops ♀×M. saxatilis ♂

Abstract

Abstract A comparative feeding trial was undertaken to evaluate the relative use of dietary carbohydrate, non-essential amino acids (NEAA), and lipids for energy by hybrid striped bass Morone chrysops ♀ × M. saxatilis ♂. The control diet was formulated to contain 40% crude protein, 25% dextrinized corn starch as available carbohydrate (CHO) and 10% lipid. In the three experimental diets, the 25% dextrinized starch was replaced with either, 25% NEAA (12.5% l -glutamate and 12.5% l -aspartate), an additional 11% lipid (21% total lipid; designated high-lipid diet), or 0% CHO with protein and lipid components concentrated to 53.3% and 13.3%, respectively, and each diet was fed to juvenile fish such that all groups received equal amounts of intact protein. Juvenile hybrid striped bass (average initial weight of 21.1 g/fish) were stocked as groups of 12 fish in 110-L aquaria containing fresh water and operated as a recirculating system. Fish in triplicate aquaria were fed each dietary treatment at a rate approaching apparent satiation for 6 weeks. Fish fed the control diet with 25% CHO or high-lipid diet had significantly ( P