Evaluation of Artificial Diets for Cultured Fish

Introduction One of the major expenses in any fish culture operation is the cost of feeds for the fish, and the profitability of many operations is frequently tied to the cost of feed. Hatchery production of fish larvae most often requires the expensive production of live food (phytoplankton and zooplankton), because artificial diets are either not available, or are grossly inadequate. Artificial diets are available for growout of fingerlings and adults of most cultured fish species, but they may be less than optimal because they had been formulated for another species. For example, in the United States,commercially formulated diets are available for catfish and salmonids, but these diets have been used without modification to feed other species of fish, including hybrid striped bass, tilapia, carps, and others. Less than optimum diets for growout of fingerlings will result in lowered growth rates and excessive waste, either by excessive fecal material, excessive urinary nitrogen, or uneaten food. Thus, less than optimum diets are not only wasteful in terms of money spent on feed, but they can cause increased waste management problems. The key challenge of producing production feeds is the maximization of fish growth with a minimization of waste.