RESUMO -Foram realizados dois experimentos com o objetivo de definir uma dieta referência para estudos de exigências nutricionais em Piaractus brachypomus. No primeiro experimento, foram testadas quatro dietas com ingredientes semipurificados (H-440 com 47% PB, C-102 com 41% PB, NRC com 37% PB e IALL-1 com 32% de PB) e uma dieta controle (32% de PB) com ingredientes comuns. No segundo experimento, foi usada a dieta IALL-1, como base para a formulação de três dietas experimentais. A dieta 2 foi suplementada com vitamina C e uma pré-mistura de macrominerais, enquanto na dieta 3 o óleo vegetal foi substituído por óleo de peixe. O ganho de peso foi usado como critério básico para medir os efeitos das dietas, sendo também considerados consumo de alimento, taxa específica de crescimento (SGR), conversão alimentar aparente (FCR), eficiência de utilização da proteína (PER) e retenção de proteína (%PPV) e de energia (%RE). Entre as dietas semipurificadas, o melhor desempenho de crescimento e de utilização dos nutrientes foi observado para as dietas NRC e IALL-1, que não diferiram entre si. No segundo experimento, o grupo de peixes alimentados com a dieta 2 apresentou crescimento 42% maior que o observado com as dietas sem suplementação. As outras variáveis analisadas, FCR, SGR, PER e %PPV, também foram significativamente melhoradas. Os resultados em conjunto indicam que a dieta IALL-1 suplementada com macrominerais e vitamina C pode ser considerada adequada como dieta referência semipurificada para estudos de nutrição de Piaractus brachypomus.Palavras-chave: dieta referência, nutrição de peixes, peixe de água doce, pirapitinga, Piaractus brachypomus Studies for Composition of Semipurified Reference Diet for Nutritional Requirements Evaluation of Juvenile Pirapitinga Piaractus brachypomus (Cuvier, 1818)ABSTRACT -Two trial experiments were conducted to determine a reference diet for nutrient requirement studies of Piaractus brachypomus. In the 1st experiment four diets elaborated with purified ingredients (H-440 with 47% PB, C-102 with 41% PB, NRC, with 37% PB and IALL-1 with 32% of PB) and a diet control (32% of PB) with common ingredients, were tested. In the 2 nd experiment the diet IALL-1 was used as base for the formulation of three experimental diets. Diet 2 contained vitamin C and macrominerals premix supplement, while in diet 3 vegetable oil was substituted by fish oil. Weight gain, taking also into account the relative food intake, specific growth rate (SGR), food conversion ratio (FCR), protein efficiency ratio (PER), protein retention (%PPV) and energy retention (%RE), was used as the basic approach for measuring the effects of the diets. The best growth performance and nutrient use among semipurified diets was observed for diets NRC and IALL-1. In the 2 nd experiment, fish fed diet 2 presented a growth (42%) greater than those fed non supplemented diets. Other analyzed variables FCR, SGR, PER and %PPV were also significantly improved. The added results indicate that macro minerals and vitamin C supplemented-die...

A growth experiment was conducted to determine the optimal dietary protein requirement for juvenile cachama, Piaractus brachypom us. Six semi-purified isoenergetic experimental diets using casein and gelatin as protein sources were formulated to contain graded levels of protein (16, 20, 24, 28, 32 and 36%)

The effects of diets with three contents of carbohydrates and lipids were evaluated on the growing performance of cachama Piaractus brachypomus juveniles (initial weight 7.8 ± 0.49 g). The experiments were performed a 3 9 3 factorial design (200, 280 and 360 g of carbohydrates and 40, 80 and 120 g of lipids kg À1 ). Protein content was kept constant in 320 g kg À1 and digestible energy between 11.3 and 16.1 MJ kg À1 . Simple effects and interaction of factors on growth performance varied significantly (P < 0.05) indicating dependence among them. The maximum weight gain was observed in fish fed 200 and 280 g kg À1 carbohydrates and 40 g kg À1 lipids. Increase of lipids from 80 to 120 g kg À1 reduced growth significantly. Protein efficiency rate and percentages of protein retention and energy were positively correlated with carbohydrate levels and no significant differences (P > 0.05) were observed with the lipid levels. Results indicate that cachama utilizes carbohydrates as energy source more efficiently than lipids; likewise, lipid levels over 40 g kg À1 depress growth at any carbohydrates level.

Una clasificación de larvas de peces considera dos tipos: altriciales y precociales, asociadas al desarrollo temprano en relación con la cantidad de yema disponible en el saco vitelínico. La etapa larval tiene como principal objetivo la obtención de nutrientes para su ontogénesis. Para su comprensión, estudios morfológicos, asociados a respuestas enzimáticas, deben ser realizados. Teniendo en cuenta que la larvicultura es el cuello de botella de los sistemas de producción en acuicultura, se pretende abordar esta revisión con el fin de comprender las relaciones entre el ambiente y los cambios que ocurren en la transformación de larvas a juveniles, con el fin de asegurar el éxito en la fase más compleja en la vida de los peces.

Resumen -El objetivo de esta investigación fue evaluar los coeficientes de digestibilidad aparente de materia seca (MS), proteína y energía de alimentos de origen animal y vegetal, utilizados en raciones para cachama (Piaractus brachypomus). Fueron formuladas 15 dietas experimentales, compuestas por 69,5% de una dieta referencia semipurificada, 0,5% de óxido de cromo y 30% del ingrediente a evaluar. En cada experimento, fueron utilizados 90 peces que se alimentaron durante cinco días con la correspondiente dieta; al quinto día, los animales fueron trasladados a tanques cónicos para recolección de heces. Los coeficientes de digestibilidad aparente (CDA) de proteína variaron de 92,1 a 84,7% entre los ingredientes proteicos de origen vegetal, de 85,0 a 68,5% en los proteicos de origen animal, y de 83,7 a 57,6% entre los de origen vegetal con baja proteína. Los CDA de energía de torta de soya, gluten de maíz, harina de yuca integral y de todos los ingredientes de origen animal arrojaron valores superiores a 76%. Los máximos CDA de MS variaron entre 71 y 78% y fueron observados en gluten, harina de yuca y en los ingredientes de origen animal. La cachama tiene alta capacidad para aprovechar eficientemente ingredientes de origen animal y vegetal.Términos para indexación: Piaractus brachypomus, coeficientes de digestibilidad, energía digestible, ingredientes alimenticios, peces tropicales, proteína digestible. Apparent digestibility of ingredients from plants and animals in cachamaAbstract -The objective of this work was to evaluate the apparent digestibility coefficients of dry matter (DM), protein and energy of ingredients from animals and plants utilized in the ration for cachama (Piaractus brachypomus). Fifteen experimental diets were formulated, which were composed by 69.5% of a semipurified reference diet, 0.5% chromium oxide, and 30% of the ingredient to be evaluated. In each experiment, 90 fish fed the corresponding diet were used; in the fifth day, fish were transferred to conical tanks for fecal sampling. The apparent digestibility coefficients (ADC) of protein varied between 92.1 and 84.7% among protein ingredients from plants, between 85.0 and 68.5% among protein ingredients from animals, and between 83.7 and 57.6% among low-protein ingredients from plants. Energy ADC of soybean meal, corn gluten, wholly yuca meal and of all ingredients from animals produced values higher than 76%. The highest values for CDA of DM varied between 71 and 78% and were observed in gluten, yuca meal and in ingredients from animals. Cachama has a high ability to efficiently benefit from ingredients from animals and plants.