Effects of carbohydrate sources on growth,body composition and tissue lipid deposition of blackspot seabream,Pagellus bogaraveo (Brunnich) |
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Authors: | Luísa M. P. Valente Mercedes Olmedo Pedro Borges Silvia Soares Emidio F. S. Gomes Blanca Álvarez‐Blázquez Gemma Pazos Fatima Linares |
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Affiliation: | 1. CIMAR/CIIMAR – Centro Interdisciplinar de Investiga??o Marinha e Ambiental, Universidade do Porto, Porto, Portugal;2. ICBAS – Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Largo Prof. Abel Salazar, Porto, Portugal;3. Instituto Espa?ol de Oceanografia, Centro Oceanográfico de Vigo, Cabo Estay, Canido, Vigo, Espa?a;4. Centro de Investigacions Mari?as, Vilanova de Arousa, Pontevedra, Espa?a |
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Abstract: | 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/m3 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. |
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Keywords: | fish nutrition nutrient utilization Pagellus bogaraveo proximate composition tissue lipid content |
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