The experiment was carried out to compare the performance of two Nile Tilapia strains (Thai and common) during the initial and growing phases. The fishes (50 in the starting phase and 40 in the growing phase) were assigned to a completely randomized design with two treatments and five replications. Better results were observed for the weight gain percentage, daily weight gain, feed:gain ratio and economic viability in both experimental phases, survival in the starting phase and final size in the […]

This study was carried out to determine the apparent digestibility coefficients (ADC) of amino acids for corn, wheat bran, soybean meal and fish meal in Nile tilapia (Oreochromis niloticus), juveniles (25.24 ± 3.88 g), fed purified pelletized reference diet containing 33.78% crude protein and 0.10% of chromic oxide (indicator). The average ADC of amino acids were: 88.31; 77.40; 91.78 and 82.58% for corn, wheat meal, soybean meal and fish meal, respectively. Althought results suggest that the protein ADC value is […]

This experiment was carried out to evaluate the effect of diets with different crude protein (CP) replacement levels of soybean meal (SBM) by canola meal (CM) on growing Nile tilapia (Oreochromis niloticus) performance and carcass characteristics. Eighty fishes (22.19 ± 0.29 g) were assigned to a block randomized design, with four treatments and five replications. The experimental diets were formulated with 0.00, 33.33, 66.67 and 100.00% levels of SBM protein replacement by the CM protein, corresponding to 0.00, 24.50, 49.00, […]

Six acclimatized incubators were initially installed in the Experimental Frog Farm of the Federal University of Viçosa and later in Experimental Frog Farm of the Federal University of Rio Grande, with the objective of accomplishing experiments to evaluate the effects of the environment on frogs performance in cages of fiber glass. Environments with temperatures of 25ºC and photoperiod of 12/12 hours of light/hours of darkness (h L/D) were available to frogs adaptation during 15 days before each experiment. The treatments […]

The objective of this research was to study the economic effect of fingerlings I common carp (Cyprinus carpio L.) population stocked in high densities on winter time with artificial supplementation and chemical manuring. A completely randomized design with four treatments (5; 10; 15 and 20 peixes/m2) and nine replicates. The fishes were stoked with average weight of 0.48 g and length. and 3.15 cm respectively in all treatments with 45 days of age. The diets were formulated with 27% PB […]

This experiment was undertaken to evaluate the effect of dietary tannin on growth performance and carcass composition of piauçu, for sixty days. Twenty one aquaria (80 L) were supplied with dechlorinated tap-water (1 L/min) in a closed system. Water quality was controled by biologic filter and heater. Fish, with inicial average weight 5.06 g, in a triplicate aquaria, were randomly assigned to each of 7 treatments. Experimental diets were formulated to contain approximately 3,200 kcal of digestible energy, 30% crude […]

This experiment was done at Hydrobiology and Pisciculture Section of the Dept of Animal Biology of the University Federal de Viçosa. Fingerlings of Hoplias lacerdae previously trained to accept artificial feed were selected for length and stocked in three tanks with 5000 liters each, until a biomass total of 36.72 g was reached. After 30 days the fishes were selected again for length and distribute into the same tanks, with density of 5 fishes/m², and left again for an additional […]

The objective of this study was to determine the nutritive values of some feeds from frogs diets, in a digestibility assay, using the forced feeding method, with 84 frogs at finishing stage (128,5 g ± 2 g) and 120 at initial stage (27,3 g ± 2 g), housed in metabolism cages. Forty frogs at initial stage and 28 at finishing stage were fasting, to determine the endogenous and metabolic losses. The values of apparent metabolizable dry matter (AMDM – %), […]

This work consisted in testing the efficiency of a masculinizing hormone (17b-hydroxy-17-methyl-androxy-4-en-3-one) in the sex reversal of bullfrog tadpoles. Three hundred and fifty two tadpoles with two or three months old, from the stages 30 to 36, were used to test four levels of hormone in the ration (0, 30, 60 and 90 mg/g), for 45 days. After metamorphosis, 167 juveniles were sacrificed and 185 were reared until the fourth month of age and sacrificed thereafter. Macroscopic analysis of the […]

The experiment was carried out, during 100 days, to study different crude protein sources and levels of diets for pacu fingerlings. Two hundred and fifty two pacu fingerlings were assigned to 36 aquariums, containing seven fishes, with 150 liters of water. During the experimental period, the average temperature of the water was 28oC and other limnology parameters (dissolved oxygen, pH, alkalinity and conductivity) remainded within the levels adopted for the good development of this specie. The experimental design consisted of […]