Determination of fatty acid requirements during weaning and first ongrowing of marine fish using a standard diet
Coutteau, P. (1996). Determination of fatty acid requirements during weaning and first ongrowing of marine fish using a standard diet, in: Gajardo, G. et al. (Ed.) Improvement of the Commercial Production of Marine Aquaculture Species: Proceedings of a workshop on Fish and Mollusc Larviculture. pp. 45-55
In: Gajardo, G.; Coutteau, P. (Ed.) (1996). Improvement of the Commercial Production of Marine Aquaculture Species: Proceedings of a workshop on Fish and Mollusc Larviculture. Impresora Creces: Santiago. , more
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Abstract |
Although the requirements for highly unsaturated fatty acids (HUFA), primarily eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), have been demonstrated for various species of marine fish, major controversies continue to exist over what constitutes the optimal dietary intake of fatty acids and the efficiency of various lipid classes in supplying essential fatty acids. Furthermore, fatty acid requirements have been determined primarily in larval stages using enriched live food and in juvenile fish using pelletized diets, whereas fatty acid requirements during and just after the critical period of weaning are poorly documented. This paper reports on the development of a standard diet that yielded acceptable growth of marine fish during weaning and first ongrowing, and in which the fatty acid composition could be manipulated without affecting other biochemical and physical characteristics of the diet. A series of experiments are reported in which the diet was used to study fatty acid requirements of two species of marine fish. European sea bass (Dicentrarchus labrax L.) and gilthead seabream (Sparus aurata L.). The (n-3) HUFA requirements of European sea bass during and immediately after weaning did not exceed 1-1.5% of the dry diet, but were dependent on the supply of (n-3) HUFA through the live prey Artemia fed prior to and during weaning. Higher levels of dietary (n-3) HUFA (up to 5.1% of the dry diet) were accumulated in the tissue of the juvenile sea bass to levels similar to those present in the diet. For seabream the ratio DHA/EPA and the form under which the (n-3) HUFA were presented in the diet (ethyl esters versus triglycerides) affected the efficiency of dietary (n-3) HUFA. The present fed preparation technology allows the production of relatively large batches of diet, which may be the first step in the development of a standard diet that would facilitate comparisons of results among laboratories, experiments and species. |
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