68 SEPTEMBER 2012 plant ingredients containing high protein content with high protein digestibility and low concentrations of anti-nutritional components are potential alternative protein sources for replacement of fishmeal in aquafeeds. Substitution of Fish Oils Nutritional quality and flavor of fish flesh depends on the amount and types of lipids it contains. Some fish are particularly rich in n-3 fatty acids that protect humans from cardiovascular diseases. The fatty acid profile of fish flesh closely resembles that in the feed. Plant oils are generally richer in n-6 fatty acids. On promising strategy is to use linseed or soybean oil during the main growth phase and then use fish oil at the end of the farming period to produce fish flesh that is enriched with n-3 fatty acids. Outlook The expansion of global aquaculture production is increasing the demand for aquafeeds. Fishmeal is a main critical protein source in aquafeed production. The increasing cost of fishmeal has encouraged feed manufacturers to look for cheaper plant proteins sources. Although many plant materials have demerits, anti-nutritional factors are the most serious concern in completely replacing fishmeal in feed formulations. Antinutritional factors have an adverse effect on feed digestibility and therefore production efficiency. Heat inactivation and water soaking are the two common detoxification methods used to overcome most anti-nutritional factors. Enzymes provide additional powerful tools that can inactivate anti-nutritional factors and enhance the nutritional value of plant-based protein in feeds. They provide a natural way to transform complex feed components into absorbable nutrients. Endogenous enzymes in the digestive system of fishes help to break down large organic molecules, such as starch, cellulose and protein, into simpler substances. Addition of enzymes in feed can improve nutrient utilization, thereby reducing feed cost and the excretion of nutrients into the environment. Presently the use of enzymes can reduce fishmeal inclusion by around 5 percent in most aquafeeds. Collaborative research efforts among fish nutritionists, agricultural scientists, and the soybean processing industry are needed. Genetic alteration of seed oils, pulses, cereals and other crops to improve their protein, amino acid and mineral profile, and eliminate undesirable compounds should also be undertaken. Researchers should identify fish growth factors in alternative, cheap, and easily available materials, making possible the reduction or elimination of fishmeal as an ingredient in aquafeeds. Notes 1 Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Belgium. 2 Center for Aquaculture Research & Development, Don Bosco Bishramganj, Tripura-799103, India 3 Central Institute of Fisheries Education (Deemed University), Mumbai, India 4 College of Fisheries, Central Agricultural University, Lembucherra, Tripura-799210, India * Corresponding author: debtanu08@gmail.com, Mobile- +919856423177 References Agbo, N. W. 2008. Oilseed meals as dietary protein sources for juvenile Nile Tilapia (Oreochromis niloticus L.). Ph.D. Dissertation. University of Stirling, Scotland, UK. Francis, G., P. S. Harinder, H. P. S. Makkar and B. Klaus. 2001. Antinutritional factors present in plant derived alternate fish feed ingredients and their effects in fish. Aquaculture 197:197-227. Glencross, B. D., M. Booth and G. L. Allan. 2007. A feed is only as good as its ingredients – a review of ingredient evaluation strategies for aquaculture feeds. Aquaculture Nutrition 13:17-34. Martinez-Palacios, C. A., R. G. Cruz, M. A. Olvera and C. Chavez-Martinez. 1988. The use of jack bean (Canavalia ensiformis Leguminosae) meal as a partial substitute for fishmeal in diets for tilapia (Oreochromis mossambicus). Aquaculture 68:165-175. Miller, J. and C. T. Young. 1977. Protein nutritional quality of florunner peanut meal as measured by rat bioassay. Journal of Agriculture and Food Chemistry 25:653-657. Makkar, H. P. S. and K. Becker. 2009. Jatropha curcas, a promising crop for the generation of biodisel and value-added coproducts. European Journal of Lipid Science and Technology 111:773-787. Makkar, H. P. S. 1993. Anti-nutritional factors in foods for livestock. Pages 69-85 In: Gill, M., E. Owen, G. E. Pollot and T. L. J. Lawrence, eds. Animal production in developing countries. Occasional publication No.16, British Society of Animal Production. Makkar, H. P. S., G. Francis and K. Becker. 2008. Protein concentrate from Jatropha curcas screw-pressed seed cake and toxic and antinutritional factors in protein concentrate. Journal of the Science of Food and Agriculture 88:1542-1548. NRC (National Research Council). 1982. United States- Canadian Tables of Feed Composition (Third Revision). National Academy Press, Washington D.C., USA. NRC (National Research Council).1998. Nutrient Requirement Of Swine (Tenth Revised Edition). National Academy Press, Washington D.C., USA. Nwokolo, E. 1987. Nutritional evaluation of pigeon pea meal. Plant Foods for Human Nutrition 37:283-290. Roehm, J. N., D. J. Lee, S. D. Polityka and R. O. Sinnhuber. 1970. The effect of dietary sterculic acid on the hepatic lipids of rainbow trout. Lipids 5:80-84. The expansion of global aquaculture production is increasing the demand for aquafeeds. Fishmeal is a main critical protein source in aquafeed production. The increasing cost of fishmeal has encouraged feed manufacturers to look for cheaper plant proteins sources.
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