The chapter provides an overview of nutrients, nutrient requirements of major farmed fish species, nutrient bioavailability, feed additives, evaluation of feed ingredients and feed, and basic concepts essential for feed formulations. Many biochemical and physiological processes transform feed components into body elements that are required for sustaining the life, growth, health, and productivity of aquatic animals. A brief description of the utilization of energy-producing nutrients (protein, lipid, carbohydrate) followed by vitamins and minerals are emphasized. An understanding of these basic nutrition concepts is essential for formulating rations and developing feeding practices for enhancing the efficiency of food production while protecting the environment and maintaining the nutritional value of fish-derived food products. In recent years, major shifts from the use of fish meals to planting ingredients have resulted in more focus on their nutrient bioavailability and evaluation of several alternated sources of protein and lipid. Current methods used in feed formulations are reviewed and future challenges are outlined.
