Effect of dietary protein and lipid levels on growth and feed utilization of white sea bream (Diplodus sargus) juveniles

• Tipo: Artigo em Revista Científica Internacional
• Data: 2006

Autores

Sa, R (Autor) Outra; Pousao Ferreira, P (Autor) Outra; Oliva Teles, A (Autor) FCUP

Revista

Título: Aquaculture Nutrition

Vol. 12

Páginas: 310-321

ISSN: 1353-5773

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 65 Citações

Scopus - 75 Citações

Classificação Científica

FOS: Ciências agrárias > Agricultura, silvicultura e pescas

Outras Informações

ID Authenticus: P-004-J03

DOI: 10.1111/j.1365-2095.2006.00434.x

Abstract (EN): In this study, two growth trials were conducted to evaluate the effect of dietary protein and lipid levels on growth and feed utilization of white sea bream (Diplodus sargus) juveniles. For the first trial, five diets were formulated to contain 120 g kg(-1) lipid and increasing levels of protein, ranging from 400 to 600 g kg(-1). Two additional diets were formulated with 400 and 600 g kg(-1) protein and 180 g kg(-1) lipids. The diets were fed to apparent visual satiety to duplicate groups of fish with a mean weight of 1.5 g for 10 weeks. For the second growth trial, four diets were formulated to contain 120 g kg(-1) lipid and 380-520 g kg(-1) protein. Two additional diets were formulated with 380 and 520 g kg(-1) protein and 180 g kg(-1) lipids. The diets were fed to apparent visual satiety to triplicate groups of fish with a mean weight of 41 g for 12 weeks. At the end of both trials, there were no growth differences among groups independent of the dietary protein content. In the first trial, growth was negatively correlated to dietary lipid levels. No significant differences of feed intake were detected among groups in both trials, but a direct correlation between feed efficiency and dietary protein level was observed. Protein efficiency ratio and nitrogen (N) retention (% N intake) significantly decreased with the increase of dietary protein levels. In both trials, energy retention (% energy intake) was highest in groups fed on diets with the highest protein-to-energy (P/E) ratio. At the end of both trials, no significant differences in whole-body composition were observed among groups. Specific activity of enzymes involved in amino acid catabolism [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and glutamate dehydrogenase (GDH)] showed no significant differences with dietary protein level in both trials. Nevertheless, in the first trial, a significantly lower GDH activity was observed in fish fed with higher dietary lipid levels. No differences were found for specific activity of the lipogenic enzymes, fatty aid synthetase and glucose-6-phosphate dehydrogenase, in the second trial. Results of this study indicate that a diet with a protein level of 380-420 g kg(-1) and a P/E ratio of 20 g protein MJ(-1) satisfies the growth requirements of D. sargus juveniles. Also, within the range tested, no evidence of protein sparing by dietary lipids seems to occur.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 12