Submitted to: Global Aquaculture Advocate
Publication Type: Popular Publication
Publication Acceptance Date: August 1, 2009
Publication Date: September 1, 2009
Citation: Lim, C.E., Aksoy, M., Klesius, P.H. 2009. Lipids and fatty acids requirements of tilapia - Dietary supplementation essential for health, reproduction. Global Aquaculture Advocate. 12(5):86-87. Technical Abstract: Tilapia have been shown to have a dietary requirement for linoleic (n-6) series fatty acids (18:2n-6 or 20: 4n-6). The optimum dietary levels of n-6 reported were 0.5 and 1% for redbelly tilapia (Tilapia zillii) and Nile tilapia (Oreochromis niloticus), respectively. Tilapia have been suggested to also have a requirement for linolenic (n-3) series of fatty acids (18:3n-3, 20:5n-3 or 22:6n-3), but the optimum dietary requirement levels for n-3 of various tilapia species have not been determined. The presence of high levels of either n-6 or n-3 may spare the requirement of the other, although n-6 appears to have better growth promoting effect than n-3. Tilapia have been shown to possess the ability to desaturate and chain elongate 18:2 n-6 to 20:4 n-6 and 18:3 n-3 to 20:5 n-3 and 22:6 n-3. Plant oils rich in n-6 and/or n-3 series of fatty acids, such as soybean oil, corn oil, sunflower oil, canola oil, palm oil products and linseed oil have been reported to be good lipid sources for tilapia. Beef tallow and pork lard are poorly utilized by tilapia. However, they can be used in combination with other lipid sources providing that the essential fatty acid requirements are met. Information on the nutritional value of fish oil for tilapia is inconsistent. Some studies have shown that the nutritional value of fish oil is similar to that of plant oils, while others reported poor performance of fish oil-containing diets. Fish oil provided good spawning performance for tilapia broodstock reared in brackishwater, while in freshwater, good reproductive performance was obtained with soybean oil. The sparing effect of dietary lipids on protein utilization has also been demonstrated. However, tilapia do not tolerate as high a dietary lipid level as do salmonids. A dietary lipid level of 5 to 12% has been suggested to be optimum in diets of tilapia.