Exigências em proteína e energia e valor biológico de alimentos para o dourado Salminus brasiliensis / Protein and energy requirements and biological value of selected feedstuffs for the dourado Salminus brasiliensis

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The dourado, Salminus brasiliensis, presents excellent farming characteristics, such as fast growth and excellent flesh quality. However, the lack of the knowledge on the species nutritional requirements and biological value of feedstuffs hamper the formulation of diets for optimized performance and, consequently, the speciesintensive farming. To determine de species nutritional requirements, juveniles dourado (5.29 ± 0.21 g) were stocked in 75 cages (60-L) set up in 1,000-L containers, and fed for 60 days diets containing levels of crude protein (CP) between 35 to 51% (4% increments) and gross energy (GE) varying of 4,200 to 5,000 kcal/kg feed (200 kcal increments). The trial was set up in a completely randomized design, 5 × 5 factorial scheme (five levels of GE and five levels of CP, with three replications). Data on weight gain (WG), percentage weight gain (PWG), daily feed consumption (DFC), food conversion ratio (FCR), specific growth rate (SGR) and nutrient retention were recorded. No interaction (P>0.05) between dietary energy and protein levels for all parameters was detected. The values of DFC, WG, RWG, FCR, SGR and nutrient retention were affected (P<0.05) by the dietary protein and energy levels. DFC decreased with increasing energy levels. The liposomatic and viscerosomatic indexes were affected (P<0.05) by dietary energy levels, and increased with increasing energy levels. Through broken line analysis technique, the requirements estimated for optimum performance and nutrient and energy retention of dourado were 45.08% CP, 4,600.0 kcal GE/kg, and a energy:protein ratio varying between 10.20 and 10.65 kcal of GE/g of CP. Apparent digestibility is one of the main tools to evaluate the potential of an ingredient to be used in aquafeeds. To evaluate the apparent digestibility coefficient (ADC) of energy and nutrients of animal and plant protein sources in practical diets for the dourado (19.49 ± 5.04 g), fish were stocked in plastic cages (80-L) and fed pelleted test diets containing 30% of test ingredients plus 70% of a reference diet (RR) containing 48.14% CP, 4,453.2 kcal GE/kg, and 0.1% of chromium oxide III. After the last daily meal, cages were transferred to cylindrical conical-bottomed aquaria (200-L) where feces were collected by sedimentation in refrigerated containers. ADCs of nutrients and energy of selected protein sources differed (P<0.01); ADC values were: 94.25; 91.26; 93.05 and 93.47% for CP, 91.03; 90.33; 87.83 and 88.78% for GE, 92.06; 84.49; 80.58 and 79.25% for ash, 83.90; 80.26; 84.25 and 84.55% for dry matter, 97.38; 96.74; 93.32 and 91.46% for lipid for fish meal (FM), poultry by-product meal (PBM), soybean meal (SBM), and corn gluten meal (CGM), respectively. The average ADC of amino acids was: 93.60; 89.95; 92.07 and 92.45% of FM, PBM, SBM and CGM, respectively. All tested ingredients were efficiently used and can partially replace FM in diets for carnivorous dourado.

ASSUNTO(S)

dieta animal digestibility dourado protein nutritional requirement protein sources digestibilidade proteínas. energia nutrição animal salminus brasiliensis dourado energy.

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