FEEDING SYSTEMS FOR RAINBOW-TROUT AND OTHER SALMONIDS WITH REFERENCE TO CURRENT ESTIMATES OF ENERGY AND PROTEIN-REQUIREMENTS

Feeding systems are defined as all feeding standards and practices used to deliver nutritionally adequate diets to animals in such a way as to maintain normal growth, health, and reproduction. Fish feeding continues to be an "art-form", with farmers, not the fish, determining feed intake even though greatly improved, nutrient-dense feeds are in general use. The paper reviews factors central to the design of effective feeding systems, addresses some limitations of systems in general use, outlines modern methods of predicting growth, and assesses energy and protein requirements in terms of biogenetics. Dietary energy and protein requirements are developed from energy intake, the protein: energy ratios of diets and nitrogen retention, and these principles are applied to define a set of feeding standards.