Crescimento e respostas hematológicas de tambaquis alimentados com diferentes quantidades de mandioca (Manihot esculenta)

Tambaqui,Colossoma macropomum is a fish of primary importance in Brazilian aquaculture and in the Amazon region in particular. The aim of this work is to analyze the combined effects of physical training and levels of dietary cassava (Manihot esculenta) on the hematological parameters, food intake, conversion efficiency, growth ratio and swimming performance of this fish. A diet for tambaqui consisting of 30% cassava caused decreases in weight gain and specific growth rate compared with the control group. Diets containing 15% or 45% cassava did not affect these indices and did not cause hematological changes in tambaqui juveniles, indicating that some amount of cassava can be used as an alternative energy source for this important aquaculture species.Tambaqui Colossoma macropomum, é um peixe de importância fundamental na aquicultura do Brasil e, em particular, na Região Amazônica. O objetivo deste trabalho foi analisar o efeito combinado do treinamento físico com diferentes níveis de macaxeira (Manihot esculenta) na dieta, sobre os parâmetros hematológicos, ingestão alimentar, eficiência de conversão, taxa de crescimento e performance natatória desses peixes. A dieta com 30% de cassava causou diminuição no ganho de peso e na taxa de crescimento específico quando se comparou ao grupo controle. Dietas contendo 15% e 45% de cassava não apresentaram efeito sobre estes índices e não causaram alterações hematológicas significativas em indivíduos juvenis de tambaqui, indicando que estas quantidades de cassava podem ser administradas como alternativa de fonte de energia para essa importante espécie na aquicultura

Feeding strategies and energy to protein ratio on tambaqui performance and physiology

The objective of this work was to evaluate the effect of feed deprivation and refeeding with diets containing different energy to protein ratios (E/P) on the performance and physiology of juvenile tambaqui (Colossoma macropomum). A 4x2 factorial arrangement with three replicates was used, with four E/P ratios (11.5, 10.5, 9.5, and 8.5 kcal g-1 digestible energy per protein) and two feeding regimens (with and without deprivation), during 60 days. Fish from the food-deprived group were fasted for 14 days and refed from the fifteenth to the sixtieth day, whereas the remaining fish were fed for 60 days. At the end of the experimental period, weight of fish subjected to food deprivation was lower than that of those continuously fed; however, this condition did not influence the physiological parameters analyzed. Tambaqui fed 11.5 kcal g-1 achieved lower final weight than those fed with the other diets, in both regimens. Among the physiological parameters, only plasma protein presented significant increase in fish fed 8.5 kcal g-1, in both feeding regimens, probably due to the higher dietary protein concentration. These results indicate that fish show a partial compensatory growth, and that 10.5 kcal g-1 can be recommended for the diet of juvenile tambaqui

Growth and hematological responses of tambaqui fed different amounts of cassava (Manihot esculenta)

ABSTRACT Tambaqui,Colossoma macropomum is a fish of primary importance in Brazilian aquaculture and in the Amazon region in particular. The aim of this work is to analyze the combined effects of physical training and levels of dietary cassava (Manihot esculenta) on the hematological parameters, food intake, conversion efficiency, growth ratio and swimming performance of this fish. A diet for tambaqui consisting of 30% cassava caused decreases in weight gain and specific growth rate compared with the control group. Diets containing 15% or 45% cassava did not affect these indices and did not cause hematological changes in tambaqui juveniles, indicating that some amount of cassava can be used as an alternative energy source for this important aquaculture species