J.F.B. Melo

Frequência de alimentação para juvenis de tambaqui

The aim of this research was to assess how often food promotes better performance in tambaqui. We tested four food frequencies (two, four, six and eight times a day) at regular intervals. Tambaqui fingerlings with initial weight of 15.74±0.28g were stocked in 16 transparent glass tanks with a capacity of 70L of usable volume in a completely randomized design with four treatments and four replications. The feeding period was thirty days and a commercial diet containing 45% crude protein for omnivorous fish and a feeding rate of 6% of the total biomass of fish for each experimental unit was used. The average results of pH, temperature °C and electrical conductivity mS/cm for morning and afternoon were respectively 6.91 and 6.96; 25.85 and 27.69; 0.65 and 0.65. We evaluated the performance indices: weight gain, feed conversion, specific growth rate, survival, and also blood glucose. No significant differences were detected for the variables studied. It is recommended that the frequency of feeding be 2 times a day for tambaqui, mainly to minimize labor.

Relação proteína:carboidrato no desempenho e metabolismo de juvenis de pacamã (Lophiosilurus alexandri)

The aim of this study was to determine the best level of inclusion between protein and carbohydrate on performance and some metabolic responses in juvenile pacama (Lophiosilurus alexandri). We tested four diets regarding protein/carbohydrate (PB: CHO) 1.24, 0.84, 0.51 and 0.33 for 60 days. The experiment was conducted with 240 juvenile pacama initially weighing 1.90g, fed twice daily (8% of the biomass). We evaluated the total weight gain, specific growth rate, feed intake, feed conversion, carcass yield and visceral fat. Glucose, total plasma free amino acids and liver glycogen were also evaluated. The relationship PB: CHO influenced (P <0.05) the performance and metabolism parameters except the liver glycogen. Higher concentrations of glucose and total plasma free amino acids were observed in fish that were fed the diet containing the highest ratio PB: CHO (1.24); and we also observed better mean weight gain, specific growth rate and feed conversion. A higher percentage of visceral fat and lower carcass yield were observed in animals treated with diet composed by the lower ratio PB: CHO (0.33). We can conclude that a diet with a ratio PB: CHO of 1.24, promotes better performance and metabolic responses in juvenile pacama.

Crescimento de tambaqui alimentado com diferentes niveis de farinha de manga e proteína na ração

The study evaluated tambaqui, Colossoma macropomum, performance fed different levels of mango (Mangifera indica) meal in the feed (20, 30, 40 and 50 %) and the reduction of protein levels (38, 33, 28 and 23 %). To this study, 240 fish were used, separated in 12 equal groups, in four treatments and three replications in a randomized system. Initial weight was 5,21; 5,24; 5,19 and 4,99 g respectively. The trial lasted 56 days and fish were periodically weight. Fish were fed daily ad libitum. The following performance parameters were analyzed: specific growth, biomass gain; apparent fed conversion, survival, metabolic profile and digestives enzymes activity. All data show positive polynomial regression for the diet with 50 % mango meal and 23 % protein (R50). Performance parameters had a significant effect with higher results in the groups were mango meal was higher and protein level was lower. Final average weigh was R20: 8,65; R30: 8,81; R40: 8,68 and R50: 11,39 g. From metabolic profile analyzes: glucose, hepatic glycogen, total amino acids and cholesterol it was observed that there are a mobilization from these metabolites in order to keep energy process for tambaqui growth. It was concluded that the best tambaqui performance occured in the diet with 50 % of mango meal inclusion and 23 % of protein. Fish metabolic profile is positively affected by the replacement of protein by mango meal.

The effect of mango waste meal in the protein:carbohydrate ratio on performance and body composition of pacamã fish (Lophiosilurus alexandri)

We evaluated the inclusion of peeled-mango waste meal as a source of carbohydrate in the protein:carbohydrate ratio (CP:CH) on performance and chemical composition of pacama (Lophiosilurus alexandri) juveniles. One hundred and fifty fish (11.31±0.96g) were stocked in sixteen 500 L tanks, fed three times daily (10% of live weight), in a system with water recirculation with biofilter. The treatments consisted of four experimental diets with decreasing levels of the ratio between crude protein and carbohydrate (1.40, 0.94, 0.56 and 0.29), with four replications per treatment. At the end of 60 days, we evaluated animal performance (final average weight gain, specific growth rate, total apparent feed intake, carcass yield, survival) and physicochemical composition of the carcass. The protein:carbohydrate ratios affected all performance variables (P 0.05). The carcass chemical composition variables were modified, except for mineral matter, pH and moisture. Mango meal can be used at the proportion of up to 15% in the diet for pacama, establishing a CP:CHO ratio of 1.40 without impairing animal performance and the carcass chemical composition.

Relação proteína:carboidrato no desempenho e no metabolismo de híbridos de Pseudoplatystoma fasciatum (fêmea) X Leiarius marmoratus (macho)

The purpose of this study was to determine the best protein:carbohydrate ratio in this hybrids diet. A water recirculation closed system was used, composed of twelve tanks with 500L each. 144 juveniles (12/tank) with initial weight of 12.63±2.52g and total length of 12.34±2.06cm were distributed. The experiment lasted for 50 days and the fingerlings were feed four diets containing different protein:carbohydrate ratios (1.24; 0.84; 0.56 and 0.33). The protein:carbohydrate ratio influenced performance. The 0.84 ratio promoted better weight gain, smaller apparent feed conversion, great feed intake and largest daily specific growth rate. In short, the 0.84 protein:carbohydrate ratio is most indicated for this hybrid. The results demonstrated metabolic mobilization of nutrients for maintenance of glucose and growth. The 0.84 protein: carbohydrate ratio was recommended for the hybrid.

Replacing cornmeal with mango meal in diets for juvenile Tambaqui Colossoma macropomum: growth and metabolic parameters

The effect on tambaqui fingerlings performance caused by diets containing two different carbohydrate sources was evaluated. Four isoproteic diets with different mango meal concentrations (0, 33, 66 and 100%) replacing cornmeal were tested. The feeding trial lasted 45 days and the feeding rate was 8% of total biomass. 240 tambaqui fingerlings with an initial weight average of 3.66g were distributed in 12 500-liter tanks in a recirculating water system with biofilter. Performance, feed intake, carcass yield, survival, total cholesterol, plasmatic free amino acids, hepatic aspartate aminotransferase(AST), hepatic glycogen and plasma glucose values were evaluated. The results showed that weight gain, daily weight gain, specific growth rate, apparent food consumption, cholesterol, AST and glycogen showed higher values in the treatments with the highest levels of mango meal. Apparent feed conversion, carcass yield, survival and plasma glucose were not affected by the two sources of carbohydrates tested. In conclusion, mango meal used in a practical diet for tambaqui improved growth performance.The effect on tambaqui fingerlings performance caused by diets containing two different carbohydrate sources was evaluated. Four isoproteic diets with different mango meal concentrations (0, 33, 66 and 100%) replacing cornmeal were tested. The feeding trial lasted 45 days and the feeding rate was 8% of total biomass. 240 tambaqui fingerlings with an initial weight average of 3.66g were distributed in 12 500-liter tanks in a recirculating water system with biofilter. Performance, feed intake, carcass yield, survival, total cholesterol, plasmatic free amino acids, hepatic aspartate aminotransferase(AST), hepatic glycogen and plasma glucose values were evaluated. The results showed that weight gain, daily weight gain, specific growth rate, apparent food consumption, cholesterol, AST and glycogen showed higher values in the treatments with the highest levels of mango meal. Apparent feed conversion, carcass yield, survival and plasma glucose were not affected by the two sources of carbohydrates tested. In conclusion, mango meal used in a practical diet for tambaqui improved growth performance.

Farelo de licuri em dietas para alevinos de tambaqui (Colossoma Macropomum, Cuvier, 1818)

The search for alternative ingredients for fish feed has become constant, therefore it is essential that the ingredients have total use by the specie. Beyond this, the ingredient should be available throughout the year. The aim of this study was to evaluate the effect of the corn meal replacement by licuri meal over tambaqui juvenile performance. Three replacement treatments were evaluated and compared to the control diet (33.33%; 66.66% and 100%). Sixteen fish (initial weight = 3.18 ± 0.5 g ) were placed in 250 L tanks. Fish were fed three times a day at the average of 5% of total biomass. Every ten days fish were weighed and measured. At the end of the trial, performance and carcass composition were evaluated in each treatment. There was no significant difference among treatments for final weight, weight gain, feed conversion, feed efficiency, survival and growth. However, there was significant difference for feed consumption, which was significantly lower where 100% of corn meal was replaced by licuri meal. Is this treatment higher carcass protein content and lower carcass fat was also significant.