Feeding Tilapia in Intensive Recirculating Systems

There are many species of tilapia, but only a few are widely cultured around the world. In the United States the most commonly cultured species of tilapia are the Nile (nilotica), Blue (aurea), Mozambique (mossambicus), Hornorum (hornorum), and hybrids such as the Taiwanese and Florida red. Choosing a species to culture depends largely on customer preference, legal status, growth rate and cold tolerance. Tilapia are well suited for culturing in ponds, cages, tanks, or raceways. Using ponds is the most popular method in the southern United States due to longer growing seasons. In the southern most parts of Texas and in Florida water temperatures can remain warm enough for year-round growth. In the cooler, temperate regions of the North and Midwest, tank culture is favored. Disciplines Aquaculture and Fisheries Comments This article is from NCRAC Fact Sheet Series #114. Used with permission. This report is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/ncrac_factsheets/6 Benefits of Culturing Tilapia in Recirculating Systems There are many species of tilapia, but only a few are widely cultured around the world. In the United States the most commonly cultured species of tilapia are the Nile (nilotica), Blue (aurea), Mozambique (mossambicus), Hornorum (hornorum), and hybrids such as the Taiwanese and Florida red. Choosing a species to culture depends largely on customer preference, legal status, growth rate and cold tolerance. Tilapia are well suited for culturing in ponds, cages, tanks, or raceways. Using ponds is the most popular method in the southern United States due to longer growing seasons. In the southern most parts of Texas and in Florida water temperatures can remain warm enough for year-round growth. In the cooler, temperate regions of the North and Midwest, tank culture is favored. Tank culture has the added benefit of reducing time and labor required for harvesting and feeding. Indoor tank culture is the preferred method when sufficient warm water is not available due to climatic conditions. There are two types of systems used for tank culture; flow-through systems, and recirculating systems. Flow-through systems are only practical if geothermal water or waste heat are available. Indoor recirculating systems offer the advantages of reduced land requirements, less water use, and environmental control for year-round growth. Recirculating systems can recycle as much as 99 percent of the culture water daily, although 90 percent recirculation is the preferred target. To make these systems cost effective the fish are generally reared intensively. Intensive recirculating tank culture can produce high yields on small plots of land with little water use. However, recirculating systems tend to be energy intensive and require high capital investments. Therefore, to make them Feeding Tilapia in Intensive Recirculating Systems by Marty Riche1 (United States Department of Agriculture, Agricultural Research Service, Fort Pierce, FL) and Donald Garling2 (Michigan State University, East Lansing, MI) profitable it is important to increase efficiency through feeding management. Feed Requirements of Tilapia in Recirculating Systems Most wild tilapia are omnivorous, meaning they will eat a variety of things, including both plants and animals. This is in contrast to many other fish that are more specialized. However, like other animals, tilapia have specific requirements for nutrients such as amino acids from protein, fats, minerals and vitamins. Fish reared in intensive recirculating systems have different nutritional requirements than those in the wild. Wild tilapia graze on blue-green algae and bacteria. This type of feeding requires a lot of energy due to finding and digesting this type of food. To meet the energy required for feeding and growth, they must consume more food relative to farm raised fish. In intensive tank culture natural food is limited. Therefore, all nutrients must be supplied in a complete pelleted diet. An advantage to feeding a pelleted diet is the higher quality and consistency of the diet. North Central Regional