ABSTRACT The objective of this study was to determine the digestible phosphorus requirement in rations for tambaqui fingerlings (Colossoma macropomum). 900 fingerlings (0.51 ± 0.06 g) were used in a completely randomized design with six treatments, five replicates, and thirty fish per experimental unit. The treatments consisted of six diets with different digestible phosphorus levels (0.12, 0.33, 0.54, 0.75, 0.95, and 1.16%). The fish were fed six times a day, for 63 days. Performance, feed efficiency, and the daily protein, fat, ash, and phosphorus deposition rates of fish were evaluated. The treatments did not influence the feed intake. The elevation of phosphorus levels increased the digestible phosphorus intake linearly, and improved of quadratic form the weight gain, specific growth rate, feed:gain ratio, protein efficiency for weight gain, and daily protein, fat, ash, and phosphorus depositions up to the estimated levels of 0.64, 0.66, 0.70, 0.70, 0.62, 0.62, 0.70, 0.71%, respectively. The phosphorus efficiency for weight gain worsened with the elevation of phosphorus levels. The recommendation of digestible phosphorus level in rations for tambaqui fingerlings to optimize weight gain and body phosphorus deposition is 0.71%, which corresponds to the estimated level of 1.04% total phosphorus. | RESUMO Objetivou-se determinar a exigência de fósforo digestível em rações para alevinos de tambaqui (Colossoma macropomum). Utilizou-se 900 alevinos (0,51 ± 0,06 g), em delineamento inteiramente casualizado, com seis tratamentos, cinco repetições, e trinta peixes por unidade experimental. Os tratamentos constituíram-se de seis rações com diferentes níveis de fósforo digestível (0,12; 0,33; 0,54; 0,75; 0,95; e 1,16%). Os peixes foram alimentados seis vezes ao dia, durante 63 dias. Avaliaram-se o desempenho, eficiência alimentar e as deposições diárias de proteína, gordura, cinzas e fósforo corporais dos peixes. Os tratamentos não influenciaram no consumo de ração. A elevação dos níveis de fósforo aumentou o consumo de fósforo digestível de forma linear, e melhorou de forma quadrática o ganho de peso, taxa de crescimento específico, conversão alimentar, eficiência proteica para o ganho, e as deposições diárias de proteína, gordura, cinzas e fósforo até os níveis estimados de 0,64%, 0,66%, 0,70%, 0,70%, 0,62%; 0,62%; 0,70%; 0,71%, respectivamente. A eficiência de fósforo para o ganho de peso piorou com a elevação dos níveis de fósforo. A recomendação dos níveis de fósforo digestível em rações para alevinos de tambaqui, visando otimizar o desempenho e a deposição corporal de fósforo, é de 0,71%, correspondendo ao nível de 1,04% de fósforo total.

ABSTRACT The common bean exhibits wide genetic variability for technological quality traits, mineral concentrations, and bioactive compounds. For this reason, investigating the correlations between those traits in common bean lines of different gene pools contributes to the progress of biofortification programs. In the present study, two recombinant inbred line populations of Mesoamerican and Andean common bean were evaluated at the F5:7 generation. Technological quality was evaluated based on mass of 100 grains and seed coat color, which was determined using a colorimeter that analyzed the L* (white to black), a* (green to red) and b* (blue to yellow) values. The concentration of six minerals and bioactive compounds (phytates and phenolic compounds) was evaluated and used to characterize the nutritional composition of the lines. The evaluated common bean lines differed (p ≤ 0.05) for all technological quality traits, mineral concentrations, and bioactive compounds, except for the zinc concentration in Andean beans. Seed coat color (L*, a*, and b* values) was highly correlated with most of the evaluated minerals and with the phytates in Mesoamerican beans. In Andean beans, seed coat color (L*, a*, and b* values) was correlated with the concentrations of potassium, magnesium, iron, and phenolic compounds. The nutritional composition of common bean lines of different classes is variable: black beans have higher concentrations of potassium, phosphorus, calcium, zinc, and phytates; carioca beans stand out with high magnesium concentration; and cranberry beans have higher concentrations of potassium, magnesium, and iron.