Exigência Protéica e Relação Energia/Proteína para Alevinos de Piracanjuba (Brycon orbignyanus) Dietary Protein Requirement and Energy to Protein Ratio for Piracanjuba (Brycon orbignyanus) Fingerlings

O objetivo do presente estudo foi determinar a exigência protéica e correspondente relação energia/proteína em dietas para alevinos de piracanjuba, Brycon orbignyanus. Seis dietas semi-purificadas isocalóricas foram formuladas para conter 3.000 kcal de energia metabolizável (EM)/kg e concentrações de proteína bruta (PB) de 24, 26, 29, 32, 36 e 42%. Para essas concentrações, as relações E/P das dietas foram de 12,3; 11,6; 10,4; 9,2; 8,5 e 7,1 kcal EM/g PB, respectivamente. As fontes de proteína, lipídios e carboidratos digestíveis foram, respectivamente, caseína/gelatina, óleo de fígado de bacalhau/óleo de soja e dextrina. Após condicionamento de cinco dias, as dietas foram fornecidas, até a saciedade, em duas alimentações diárias, a 162 alevinos (27 peixes/dieta), que apresentaram 8,38 ± 0,09 g de peso médio inicial, distribuídos em 18 tanques de fibra-de-vidro de 100 L, conectados a um sistema de recirculação de água. A temperatura média da água foi de 26,3°C, com extremos de 23,7 e 30,2°C. Após 90 dias, a concentração de proteína na dieta que proporcionou ganho em peso máximo aos peixes foi 29% PB, com relação E/P igual a 10,4 kcal EM/g PB. As dietas com concentrações de PB iguais a 32, 36 e 42% não se mostraram superiores para conversão alimentar, taxa de eficiência protéica, valor produtivo da proteína e retenção de energia bruta. A deposição corporal de proteína e gordura não sofreu influência da concentração de PB da dieta<br>The aim of this study was to determine the dietary protein requirement and associated energy to protein (E/P) ratio for "Piracanjuba", Brycon orbignyanus, fingerlings. Casein-gelatin semipurified diets were formulated to contain six crude protein (CP) concentrations: 24, 26, 29, 32, 36 e 42% at one energy level, 3,000 kcal metabolizable energy (ME)/kg. These diets resulted in E/P ratios of 12.3, 11.6, 10.4, 9.2, 8.5 and 7.1 kcal ME/g CP, respectively. The protein, lipid and digestible carbohydrate sources were casein/gelatin, cod liver oil/soybean oil and dextrin, respectively. After an initial 5-day conditioning period, each experimental diet was fed to satiation, twice a day, to 8.38 ± 0.09 g piracanjuba fingerlings (n = 27), housed in eighteen 100-L fiberglass tanks connected to a water recirculating system, and kept at 26.3°C average water temperature (range: 23.7 to 30.2°C). After 90 days, the lowest dietary CP level that produced maximum fish weight gain was 29% CP with associated E/P ratio of 10.4 kcal ME/g CP. Higher dietary CP levels, i.e., 32, 36 and 42% did not improve 29% CP feed conversion, protein efficiency ratio, apparent net protein utilization and gross energy retained. Whole-body fish composition (total lipid and protein concentration) was not affected by the dietary CP leve

The case for strategic international alliances to harness nutritional genomics for public and personal health

Nutrigenomics is the study of how constituents of the diet interact with genes, and their products, to alter phenotype and, conversely, how genes and their products metabolise these constituents into nutrients, antinutrients, and bioactive compounds. Results from molecular and genetic epidemiological studies indicate that dietary unbalance can alter gene-nutrient interactions in ways that increase the risk of developing chronic disease. The interplay of human genetic variation and environmental factors will make identifying causative genes and nutrients a formidable, but not intractable, challenge. We provide specific recommendations for how to best meet this challenge and discuss the need for new methodologies and the use of comprehensive analyses of nutrient-genotype interactions involving large and diverse populations. The objective of the present paper is to stimulate discourse and collaboration among nutrigenomic researchers and stakeholders, a process that will lead to an increase in global health and wellness by reducing health disparities in developed and developing countries. © The Authors 2005