Effects of carbohydrate sources on growth, body composition and tissue lipid deposition of blackspot seabream, Pagellus bogaraveo (Brunnich).
Rearing blackspot seabream has been associated with low growth rates and excessive lipid accumulation, resulting in a reduction of the edible yield. The effect of extruded diets containing different carbohydrate sources (wheat vs. wheat bran) was evaluated on 100 g blackspot seabream growth performance, feed utilization and fat deposition, taking into consideration the optimal dietary protein and lipid level described for smaller-sized fish. A fish meal-based diet was also tested as a control to assure maximal growth rates were achieved. The experiment was held in sea cages at environmental conditions. Duplicate groups of fish were distributed among six cages with a stocking density of 1.3 kg/m(3) and hand-fed each diet for 7 months. At the end of the experiment, fish in all groups doubled their body weight attaining 190-230 g. Specific growth rate (0.3-04), feed conversion ratio (1.3-1.6) and protein gain (0.5-0.6 g/kg/day) were similar among treatments. The Hepatosomatic Index, the Viscerosomatic Index and final whole body composition did not vary significantly among dietary treatments; nevertheless, the inclusion of wheat bran induced a significant increase of liver lipid content and the highest mesenteric fat index. All diets were effective in reducing whole body and mesenteric fat compared with initial values.
Valente
Luísa M P
LM
CIMAR/CIIMAR, Universidade do Porto, Porto, Portugal. lvalente@icbas.up.pt
Olmedo
Mercedes
M
Borges
Pedro
P
Soares
Silvia
S
Gomes
Emidio F S
EF
Alvarez-Blázquez
Blanca
B
Pazos
Gemma
G
Linares
Fatima
F
D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition / Q000187:drug effects*; D004032:Diet / Q000662:veterinary; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004043:Dietary Fiber; D004334:Drug Administration Schedule; D050356:Lipid Metabolism; D008055:Lipids / Q000032:analysis*; D021541:Sea Bream / Q000254:growth & development* / Q000502:physiology*; D014908:Triticum
D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D008055:Lipids