Water temperature does not affect protein sparing by dietary carbohydrate in Senegalese sole (Solea senegalensis) juveniles |
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Authors: | Inês Guerreiro Helena Peres Carolina Castro Amalia Pérez‐Jiménez Manuela Castro‐Cunha Aires Oliva‐Teles |
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Institution: | 1. CIMAR/CIIMAR ‐ Centro Interdisciplinar de Investiga??o Marinha e Ambiental, Universidade do Porto, , Porto, Portugal;2. Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, , Porto, Portugal;3. Departamento Zoología, Facultad de Ciencias, Universidad de Granada, , Granada, Spain;4. A. Coelho & Castro Lda, Pra?a Luís de Cam?es, , Póvoa de Varzim, Portugal |
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Abstract: | The effect of dietary protein reduction balanced by an increase in carbohydrate (starch) level on growth performance, feed utilization and intermediary metabolism of Senegalese sole juveniles was evaluated at two temperatures, 12 and 18°C. For that purpose two isolipidic (16% lipids) diets were formulated to contain 550gkg?1 protein and 90gkg?1 starch (diet HP:LC), and 450gkg?1 protein and 200gkg?1 starch (diet LP:HC). Each experimental diet was fed to triplicate groups of 20 fish (initial body weight: 15.9g) within each temperature. Diets had no effect on growth and feed utilization. Temperature affected growth but not feed efficiency, with fish growing more at 18°C. Fatty acid synthetase and glutamate dehydrogenase activities were higher at 12°C than at 18°C while activity of the other measured enzymes was not affected by water temperature. Glucokinase and malic enzyme activities were lower while fructose 1,6‐bisphosphatase activity was higher in fish fed the HP:LC diet. Our data suggest that protein can be reduced from 550 gkg?1 to 450 gkg?1 by increasing starch level in high lipid diets for Senegalese sole juveniles without affecting overall performance. A reduction in protein content through an increase in dietary starch decreases hepatic gluconeogenesis. Increasing temperature from 12°C to 18°C improves fish growth but does not affect feed efficiency. |
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Keywords: | Flatfish starch protein sparing temperature intermediary metabolism |
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