Feeds

Incorporation of Omega-3 Fatty Acids in Nile Tilapia Fed Chia Bran

Abstract

This study evaluated the effect of the inclusion of chia bran in the diet of Nile tilapia on the composition of n-3 fatty acids (FA). Omega-3 fatty acids provide health benefits such as reducing the risks of coronary heart disease, hypertension and inflammation, and the precursor alpha-linolenic acid is considered strictly essential because it cannot be synthesized by humans, therefore must be ingested. Tilapias grown in tanks for a period of 45 days were treated with diets supplemented with either soybean oil (TI) or chia bran (TII). Proximal composition analysis of the feeds showed no significant difference. Feed FA quantification showed that the chia diet (TII) had a higher alpha-linolenic acid (LNA) content. A significant increase was observed in the concentrations of LNA (8.38–81.31 mg 100 g−1 fillets), eicosapentaenoic acid (1.12–1.56 mg 100 g−1 fillets) and docosahexaenoic acid (19.55–26.55 mg 100 g−1 fillets) in tilapia fillets between 0 and 45 days for TII. Total lipids at 45 days under TII were fractionated into neutral lipids (67.66 %) and polar lipids (18.90 %). Thus, dietary supplementation with chia bran contributed to raising the nutritional quality of Nile tilapia fillets.

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Introduction to Tilapia Nutrition

By Kevin Fitzsimmons
University of Arizona
One of the great advantages of tilapia for aquaculture is that they feed on a low trophic level.  The members of the genus Oreochromis are all omnivores, feeding on algae, aquatic plants, small invertebrates, detrital material and the associated bacterial films.  The individual species may have preferences between these materials and are more or less efficient depending on species and life stages in grazing on these foods.  They are all somewhat opportunistic and will utilize any and all of these feeds when they are available.  This provides an advantage to farmers because the fish can be reared in extensive situations that depend upon the natural productivity of a water body or in intensive systems that can be operated with lower cost feeds.
In extensive aquaculture, the fish will be able to grow by eating algae and detrital matter and the farmer can grow more fish in a given area because the fish are depending directly on the primary productivity of the body of water, primary consumers.  Fish which feed on a higher trophic level, eating larger invertebrates or small fish, are secondary consumers and a system can only support a fraction of the biomass of secondary consumers compared to primary consumers.
In intensive systems, tilapia have the advantage that they can be fed a prepared feed that includes a high percentage of plant proteins.  Carnivorous fish require fish meal or other animal proteins in their diets, which in general are more expensive than plant proteins.  Nutritional studies which substitute plant proteins supplemented with specific amino acid supplements may lower costs, but still not to the level that can be achieved with tilapia diets.
Complete diets are used in systems that cannot provide any [...]