Supplementation of Vitamins, Minerals, Enzymes and Antioxidants in Fish Feeds

The fast increase in marine aquaculture productions has generated some problems related to optimization of fish feed. Moreover, the search for alternative raw materials to supplement or replace fishmeal and fish oil has made the introduction of additives into the diet necessary. Diet additives have recently attracted attention and investments of the aquaculture industry and, consequently, researches aimed at evaluating the costs/benefits ratio and the effects on organisms and environments are increasing. In general, additives are nutritive or nonnutritive ingredients that are added to the diet alone or in combination each other, and that are present in small quantities. Their functions are different: preserve the physical and chemical features of the diet, enhance animal health and welfare, improve the quality of final product and maintain the quality of aquatic environment. This chapter provides an overview on the use of vitamins, minerals, and antioxidants in fish feeds. In addition to these natural substances, also enzymes are proposed as new alternative aquafeed additives. The effects on fish growth, welfare, reproduction and health status of the above-reported additives are discussed.