Portal de Pesquisa da BVS Veterinária

Tese em Português | VETTESES | ID: vtt-200660

Resumo

O objetivo do presente trabalho foi investigar a capacidade do tambaqui (Colossoma macropomum) em compor uma dieta equilibrada utilizando mecanismos de percepcao pos ingestivas, alem de avaliar o consumo energetico apos desafios nutricionais como a diluicao e restricao de proteina. O experimento foi conduzido no Laboratorio de Nutricao e Comportamento Alimentar de Peixes na Universidade Federal do Reconcavoda Bahia, durante o periodo de marco a abril de 2015. Foram utilizados 30 juvenis de Colossoma macropomum (71,37 g ± 2,58). Os juvenis foram distribuidos em seis tanques de 250L, cinco peixes por tanque. Foram formuladas tres dietas contendo ingredientes purificados, de modo que, apenas um macronutriente fosse presente em cada composicao: proteina (P) ou carboidrato (C) ou lipidio (L). Estas dietas foram encapsuladas em capsulas de cores distintas, onde os peixes tinham a opcao de apenas associar o codigo de cores com as questoes pos ingestivas das dietas. O periodo experimental foi composto por tres etapas: etapa 01 - macronutientes puros; etapa 02 proteina diluida em 15%; etapa 03 - restricao de proteina. Todas essas etapas tiveram o intuito de oferecer um desafio nutricional e avaliar a capacidade dos peixes em compor uma dieta equilibrada. Os dados obtidos foram analisados usando um one-way ANOVA e teste de Tukey post hoc para examinar comparacoes de pares significativos. A evolucao da selecao de macro nutrientes foi expressa considerando o total de P, C e L como 100%, de dieta total. Durante a primeira etapa os peixes selecionaram uma dieta contendo em media 46,19% de proteina (P); 32,91% de carboidrato (C); 20,90% de lipidio (L). Na segunda fase a dieta de proteina foi diluida em 15%, entretanto a ingestao proteica foi mantida, pelo aumento da ingestao da dieta diluida. Dessa forma os peixes mantiveram a porcentagem de selecao entre os nutrientes. Contudo, foi observado que os peixes diminuiram o consumo energetico ao final do experimento, provavelmente devido aos animais estarem em um estagio de desenvolvimento. A media de selecao de macronutrientes entre as etapas 1 e 2 tiveram a seguinte conformacao: 45,36% P; 33,32% C; 21,32% L representando o alvo de ingestao para essa especie. Nao houve diferenca estatistica entres as fases. Durante a terceira etapa os peixes foram privados de se alimentarem da capsula de proteina, contudo, demonstraram a capacidade de manter o consumo energetico da etapa anterior, incrementando o consumo das dietas ricas em carboidrato e lipidio. Estes dados, revelam a capacidade do tambaqui em selecionar macronutrientes compondo uma dieta equilibrada atendendo suas necessidades fisiologicas, alem de defender um padrao de ingestao quando desafiados com a diluicao de proteina.

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This work aims to investigate the ability of tambaqui (Colossoma macropomum) in composing a balanced diet using post ingestive perception mechanisms, and to evaluate the energy consumption following nutritional challenges such as protein dilution and restriction. The experiment was carried out in the Fish Nutrition and Feeding Behavior Laboratory at Universidade Federal do Reconcavo da Bahia, during the period from March to April 2015. A total of 30 juvenile Colossoma macropomum (71.37 g ± 2.58) were used. Juveniles were distributed in six 250-liter tanks, five fish per tank. Three diets containing purified ingredients were formulated, so that only one macronutrient was present in each composition: Protein (P) or carbohydrate (C) or lipid (L). These diets were encapsulated in capsules of different colors, where the fish had the option to only associate the color code to the diets post feeding behavior issues. The experimental period was composed by three stages: stage 01 - pure macronutrients; stage 02 - dilute protein at 15%; stage 03 - protein restriction. All these stages were designed to offer a nutritional challenge and assess the fishs ability to compose a balanced diet. Data were analyzed using a one-way ANOVA and post hoc Tukey test to examine comparisons of significant peers. The evolution on the selection of macro nutrients was expressed considering the total P, C and L as 100%, of the total diet. During the first stage the fish selected a diet containing on average 46.19% of protein (P); 32.91% carbohydrate (C); 20.90% lipid (L). In the second phase protein diet was diluted by 15%; however the protein intake was maintained by increasing intake of diluted diet. Thus the fish kept the percentage of selection between nutrients. However, it was observed that fish decrease the energy consumption at the end of the experiment, probably because the animals are in a developmental stage. The average macronutrient selection between steps 1 and 2 had the following conformation: 45.36% P; 33.32% C; 21.32% L representing the intake target for this species. There was no statistical difference among the stages. During the third stage the fish were deprived of the protein capsule but they demonstrated the ability to maintain energy consumption from the previous stage, increasing the consumption of diets rich in carbohydrates and lipids. These data reveal the tambaquis ability to select macronutrients composing a balanced diet given their physiological needs, in addition to defending a feeding pattern when challenged with protein dilution.

Biblioteca responsável: BR68.1