Dietary lysine requirement of juvenile gilthead seabream Sparus aurata L.

TitleDietary lysine requirement of juvenile gilthead seabream Sparus aurata L.
Publication TypeJournal Article
Year of Publication2006
AuthorsMarcouli, PA, Alexis MN, Andriopoulou A, Iliopoulou-Georgudaki J
JournalAquaculture Nutrition
Pages25 - 33
KeywordsDietary lysine, Indispensable amino acids, Requirements, seabream, Sparus aurata

The dietary lysine requirement of juvenile gilthead seabream was determined by the growth response of duplicate groups of fish (3.5 g initial weight) fed on six isonitrogenous (427 g kg -1) and isolipidic (135 g kg -1) diets containing graded levels of crystalline l-lysine HCl, with dietary lysine content ranging from 36.3 to 79.7 g kg -1 of protein. The final indispensable amino acid profile of the diets except for lysine was formulated so as to resemble that of wild seabream whole body. Except for the reduced growth performance of fish groups fed the lysine-deficient diets no other deficiency signs were apparent. Survival observed throughout the feeding period of 6 weeks was excellent. Weight gain (in %), specific growth rate, feed efficiency and daily protein deposition (DPD) were significantly improved in response to the increasing levels of dietary lysine up to 52.7 g kg -1 of protein and remained nearly constant thereafter. Whole-body protein content followed a similar pattern as growth parameters in relation to dietary lysine level. Non-linear regression analysis of DPD against dietary lysine level using the four-parameter saturation kinetic model indicated a lysine requirement of 50.4 g kg -1 of protein for this species to support growth. © 2006 Blackwell Publishing Ltd.


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