Interactive Effects of Dietary Protein and Lipid on Growth and Protein Utilization of Age-0 Striped Bass

Nine dietary combinations of crude protein (37, 47, or 57%) and lipid (7, 12, or 17%) concentrations were evaluated for their effects on growth, feed efficiency, protein-efficiency ratio, protein retained, and whole-body composition of age-0 striped bass Morone saxatilis (initial mean weight, 1.4 g) over 10 weeks. Increasing dietary protein concentration generally improved weight gain of striped bass. Striped bass fed diets containing 37% crude protein plus 7% lipid had lower weight gain than fish fed 47% crude protein plus 12% lipid or 57% crude protein plus 17% lipid. Whole-body protein concentrations increased with higher dietary protein concentrations and lower dietary lipid concentrations. Highest whole-body protein concentration occurred in fish fed 57% crude protein plus 7% lipid. Lowest whole-body protein concentration occurred in fish fed 37% crude protein plus 17% lipid. Whole-body lipid concentrations increased with higher dietary lipid concentrations and lower dietary protein concentrations. Highest whole-body lipid concentration occurred in fish fed 37% protein plus 17% lipid. Lowest whole-body lipid concentration occurred in fish fed 57% crude protein plus 7% lipid. Feed efficiency, protein-efficiency ratio, and protein retained increased as dietary lipid concentration increased. Feed efficiency also increased as dietary protein increased.