Effects of dietary amino acid profile on growth performance, key metabolic enzymes and somatotropic axis responsiveness of gilthead sea bream (Sparus aurata).

TY - JOUR

T1 - Effects of dietary amino acid profile on growth performance, key metabolic enzymes and somatotropic axis responsiveness of gilthead sea bream (Sparus aurata).

AU - Gomez-Requeni, P.

AU - Mingarro, M.

AU - Calduch-Giner, J. A.

AU - Medale, F.

AU - Martin, Samuel Allen Moore

AU - Houlihan, Dominic Francis Joseph

AU - Kaushik, S. J.

AU - Perez-Sanchez, J.

PY - 2003

Y1 - 2003

N2 - Juvenile gilthead sea bream were fed to visual satiety with isonitrogenous diets based on fish meal and different plant ingredients (33-35% replacement) supplemented with free amino acids to meet the desired indispensable amino acid (IAA) profile and dispensable amino acid (DAA) content. In diets M and AT, IAA profile and DAA content resemble that of the muscle or whole body, respectively. In diets MGlu and WBGlu, DAA content was increased by adding L-glutamic acid (Glu) and thus the IAA/DAA ratio varied from 1.13 (diet M) to 0.80 (diet WBGlu). Growth rates were not significantly different among experimental groups, but feed conversion ratio and nitrogen retention were impaired by the decrease of dietary IAA/DAA ratio. Postprandial ammonia excretion increased with the increase of dietary DAA content irrespective of IAA profile. Conversely, hepatic activity of glutamate dehydrogenase (GDH) was lower in fish fed diet WBGlu than in fish fed diet M. Hepatic growth hormone (GH) binding was not significantly affected by the dietary treatment, but circulating levels of insulin-like growth factor-I (IGF-I) and GH were, respectively, down- and up-regulated in fish fed diet WBGlu, which suggests some defect in the transmission of GH receptor signal. Fat retention and hepatic activities of lipogenic enzymes (glucose-6-phosphate dehydrogenase, G6PD; malic enzyme, ME) were decreased in fish fed diet MGlu. Key metabolic enzymes of hepatic glycolysis (glucokinase, GK) and gluconeogenesis (phosphoenolpyruvate carboxykinase, PEPCK) were also altered in this group of fish. Since soybean meal concentration was highest in diet MGlu, results on lipid and carbohydrate metabolism can be primarily attributed to this component of the diet. In contrast, data on growth performance, ammonia excretion and GH axis mainly reflect changes in the dietary amino acid profile, which reveals that a muscle IAA profile and a high IAA/DAA ratio are important in feeds for gilthead sea bream. (C) 2003 Elsevier Science B.V. All rights reserved.

AB - Juvenile gilthead sea bream were fed to visual satiety with isonitrogenous diets based on fish meal and different plant ingredients (33-35% replacement) supplemented with free amino acids to meet the desired indispensable amino acid (IAA) profile and dispensable amino acid (DAA) content. In diets M and AT, IAA profile and DAA content resemble that of the muscle or whole body, respectively. In diets MGlu and WBGlu, DAA content was increased by adding L-glutamic acid (Glu) and thus the IAA/DAA ratio varied from 1.13 (diet M) to 0.80 (diet WBGlu). Growth rates were not significantly different among experimental groups, but feed conversion ratio and nitrogen retention were impaired by the decrease of dietary IAA/DAA ratio. Postprandial ammonia excretion increased with the increase of dietary DAA content irrespective of IAA profile. Conversely, hepatic activity of glutamate dehydrogenase (GDH) was lower in fish fed diet WBGlu than in fish fed diet M. Hepatic growth hormone (GH) binding was not significantly affected by the dietary treatment, but circulating levels of insulin-like growth factor-I (IGF-I) and GH were, respectively, down- and up-regulated in fish fed diet WBGlu, which suggests some defect in the transmission of GH receptor signal. Fat retention and hepatic activities of lipogenic enzymes (glucose-6-phosphate dehydrogenase, G6PD; malic enzyme, ME) were decreased in fish fed diet MGlu. Key metabolic enzymes of hepatic glycolysis (glucokinase, GK) and gluconeogenesis (phosphoenolpyruvate carboxykinase, PEPCK) were also altered in this group of fish. Since soybean meal concentration was highest in diet MGlu, results on lipid and carbohydrate metabolism can be primarily attributed to this component of the diet. In contrast, data on growth performance, ammonia excretion and GH axis mainly reflect changes in the dietary amino acid profile, which reveals that a muscle IAA profile and a high IAA/DAA ratio are important in feeds for gilthead sea bream. (C) 2003 Elsevier Science B.V. All rights reserved.

KW - dietary amino acids

KW - ammonia excretion

KW - protein accretion

KW - lipogenesis

KW - glycolysis

KW - gluconeogenesis

KW - growth hormone

KW - insulin-like growth factor-I

KW - gilthead sea bream

KW - TROUT ONCORHYNCHUS-MYKISS

KW - BASS DICENTRARCHUS-LABRAX

KW - IMPROVED NUTRITIONAL QUALITY

KW - TURBOT PSETTA-MAXIMA

KW - RAINBOW-TROUT

KW - HORMONE RECEPTOR

KW - FISH-MEAL

KW - HEPATIC LIPOGENESIS

KW - PROTEIN-SOURCES

KW - SOYBEAN-MEAL

U2 - 10.1016/S0044-8486(02)00654-3

DO - 10.1016/S0044-8486(02)00654-3

M3 - Article

VL - 220

SP - 749

EP - 767

JO - Aquaculture

JF - Aquaculture

SN - 0044-8486

IS - 1-4

ER -