Physiology of Finfish and Shellfish (2+1)

4.1.14. Least Cost Ration Formulation

The goal of production animal nutrition is the use of a scientifically formulated least cost ration. This can only be done if the nutritional requirements of the animal have been determined. The precise needs for crude protein, fat, carbohydrate, vitamins and individual amino acids was not determined for any fish until the 1950's when the necessary research for rainbow trout was completed. At this time, complete nutritional requirements are only known for salmon and channel catfish as well as rainbow trout, though this will probably be determined soon for tilapia. Once the nutritional requirements are known, a ration can be formulated that meets those requirements by combining various commercially available feedstuffs (soybean meal, corn meal, fish meal, feather meal, etc.) in the combination of ingredients that meets the fish's nutritional needs at minimum cost. The formula is then mixed and extruded into pellets. Such dry diets have a fairly long shelf life and are easy to store and handle.