Next generation fish feeds for sustainable aquaculture

Abstract

Use of fish feeds in aquaculture can be considered as the most important factor contributing to increased fish production for the growing human population on planet earth. Growth of this sector can easily be distinguished into three generations – 1st generation was extensive in nature where cultured fish was dependent on the natural fish food organisms, 2nd generation was semi-intensive where fish was dependent on supplemental feeds in addition to the natural fish food organisms and 3rd generation was intensive where fish was fed with complete artificial feeds containing all nutrients necessary for normal growth and maintenance of fish. The present generation of aquaculture can be called 4th generation, where fish is reared with customized feeds (with precise/ accurate nutrient concentrations, pellet diameter, buoyancy/ sinking characteristics, water stability etc.) with use of demand feeders, automatic feeders, medicated feeds and feeds developed for special purposes such as early or repeated maturation. This can also be called precision aquaculture. The rapid growth of the sector was possible because of understanding of the science of feeding fish to ensure its optimal development, health and maintenance called fish nutrition. In recent years, fish nutritional practices have gained increasingly important role, not only for economic optimization, but also for sustainability of aquaculture. Supplying various nutrients to meet the requirements of the cultured fish is fundamental in achieving optimal growth and production efficiency and hence maximizing economic return. The natural feeding habits of a particular fish give us useful clues on its requirement for various nutrients. There is wide range of raw materials (ingredients) available to feed a particular species of fish, and hence an infinite number of combinations of those ingredients that correspond to the formulae of utilizable feeds. Knowledge on the nutrient requirements of the cultured fish along with the chemical composition of raw materials would help the nutritionist to formulate an optimally utilizable feed. However, the best formulated feed is the one that meets the requirements of the cultured fish at minimum cost without adversely affecting the environment.