Publication

2004-03

English

http://archimer.ifremer.fr/doc/2004/publication-392.pdf (0.41 Mo)

2004 Elsevier B.V. All rights reserved

Boujard Thierry, Gelineau Anne, Coves Denis, Corraze Genevieve, Dutto Gilbert, Gasset Eric, Kaushik Sadasivam

IFREMER, Stn Expt Aquaculture, Lab Rech Piscicole Mediterraneee, F-34250 Palavas Les Flots, France.
INRA, Stn Hydrobiol, IFREMER, Unite Mixte,Lab Nutr Poissons, F-64310 St Pee Sur Nivelle, France.

Aquaculture (0044-8486) (Elsevier), 2004-03 , Vol. 231 , N. 1-4 , P. 529-545

37

Aquaculture

Phosphorus excretion, Feed intake, Lipid, Digestible energy, European sea bass, Dicentrarchus labrax

Three practical isoproteic (54% protein) diets were formulated to contain graded levels of crude fat (diet L: 10%, diet M: 20% and diet H: 30%). Each diet was assigned unrestrictedly to three and restrictedly to two replicate groups of fish (IBW 243 g). In unrestricted groups, increasing the dietary lipid level led to a significant decrease in voluntary feed intake without affecting growth rate. In the feed-restricted groups, daily growth rates increased with increasing dietary fat levels. There was a significant and inverse effect of the dietary fat content on whole body moisture and fat levels, with highest lipid (ca. 20%) and lowest moisture (ca. 58%) contents in sea bass fed diet containing the highest lipid level; muscle lipid concentration was however not affected. Nitrogen retention was significantly increased by an increase in lipid concentration in the diets, with better efficiencies observed in unrestricted (ca. 31%) than in restricted groups (ca. 27%). Nitrogen loss was significantly affected by both the feeding level and the diet composition, with lowest values (ca. 60 g kg(-1)) in groups fed diet H unrestrictedly and highest values (ca. 90 g kg(-1)) in groups fed diet L at a restricted level. Soluble phosphorus excretion in H groups was less than half that in L groups, regardless of the feeding level.