Feeding rate for pacu reared in net cages (original) (raw)
Related papers
Levels of crude protein in diets for pacu (piaractus mesopotamicus) from 150 to 400g reared in cages
Archivos de Zootecnia
A limiting factor in the production of aquatic organisms refers to the formulation of low cost diets with protein sources that meet the nutritional requirements of animals. Therefore, this study aimed to evaluate the growth performance of reared caged pacu (Piaractus mesopotamicus) in the Itaipu reservoir. Fish with an average initial weight of 150.5 ± 2.1 g were randomly distributed in 20 cages (100 fish/cage) and fed one of five levels of crude protein (CP) (18.5, 20.7, 23.7, 25.6, and 28.3 %), three times a day until apparent satiety. Growth performance, muscle composition and hematological profile were evaluated. A quadratic effect was observed (p<0.05) on the average final weight and average weight gain. A linear effect was observed on the feed conversion rates, moisture and muscle fat. The results from the carcass yield and hematological profiles did not present differences (p>0.05). The derivation of the equations indicated that the required percentage of CP in the diet...
Aquaculture Nutrition, 2010
Improper dietary protein and energy levels and their ratio will lead to increased fish production cost. This work evaluated effects of dietary protein : energy ratio on growth and body composition of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5 ± 0.4 g) were fed twice a day for 10 weeks until apparent satiation with diets containing 220, 260, 300, 340 or 380 g kg−1 crude protein (CP) and 10.9, 11.7, 12.6, 13.4 or 14.2 MJ kg−1 digestible energy (DE) in a totally randomized experimental design, 5 × 5 factorial scheme (n = 3). Weight gain, specific growth rate increased and feed conversion ratio (FCR) decreased significantly (P < 0.05) when CP increased from 220 to 271, 268 and 281 g kg−1 respectively. Pacu was able to adjust feed consumption in a wide range of dietary DE concentration. Fish fed 260 CP diets showed best (P < 0.05) protein efficiency ratio and FCR with 11.7–12.6 MJ kg−1; but for the 380 CP-diets group, significant differences were observed only at 14.2 MJ kg−1 dietary energy level, suggesting that pacu favours protein as energy source. DE was the chief influence on whole body chemical composition. Minimum dietary protein requirement of pacu is 270 g kg−1, with an optimum CP : DE of 22.2 g MJ−1.
Aquaculture Research, 2009
Haematopoiesis and blood cells' functions can be influenced by dietary concentration of nutrients. This paper studied the effects of dietary protein:energy ratio on the growth and haematology of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5±0.4 g) were fed twice a day for 10 weeks until apparent saciety with diets containing 220, 260, 300, 340 or 380 g kg−1 crude protein (CP) and 10.88, 11.72, 12.55, 13.39, 14.22 MJ kg−1 digestible energy (DE) in a totally randomized experimental design, 5 × 5 factorial scheme (n=3). Weight gain and specific growth rate were affected (P<0.05) by protein level only. Protein efficiency ratio decreased (P<0.05) with increasing dietary protein at all levels of dietary energy. Daily feed intake decreased (P<0.05) with increasing dietary energy. Mean corpuscular haemoglobin concentration was affected (P<0.05) by DE and interaction between dietary CP and DE. Total plasma protein increased (P<0.05) with dietary protein and energy levels. Plasma glucose decreased (P<0.05) with increasing dietary protein. The CP requirement and optimum protein:energy ratio for weight gain of pacu fingerlings, determined using broken-line model, were 271 g kg−1 and 22.18 g CP MJ−1 DE respectively. All dietary CP and DE levels studied did not pose damages to fish health.
International Journal of Aquaculture, 2013
This study aimed at testing the feeding rates on growth performance of pirarucu juveniles, Arapaima gigas, reared in cages. A 210-day experiment was conducted in four cages installed at the Pereira de Miranda reservoir (Pentecoste, Ceará, Brazil). Pirarucu juveniles (1550.0±85.0 g and 59.2±1.15 cm) were stocked at 40 fish/cage and fed four times a day with a commercial extruded feed with 40% crude protein. Fish were fed at rates of 2.0% and 3.0% body weight/day during the experiment. Growth performance was investigated in a designed experiment employing two different feeding rates and each treatment had two replicate cages. Survival was high and not significantly affected by feeding rate. Mean survival rate ranged between 91.2±1.2 and 92.5±2.5%. Feeding rate not affect significantly final mean length (89.8±3.2 to 88.7±3.5 cm), final mean weight (6800.0±170.0 to 6680.0±420.0 g) and production (46.8±0.7 to 46.0±1.2 kg/m 3), but FCR was significantly affected by feeding rate. Feed conversion rates were 4.32±0.08 and 2.82±0.09 for fish fed with 3% and 2% body weight/day, respectively. Therefore, the data obtained suggest that pirarucu juveniles with weight ranged from 1550.0±85.0 to 6800.0±170.0 g could be fed with feeding rate of 2.0% body weight/day.
Boletim do Instituto de Pesca
The present study evaluated practical diets with increasing levels of protein and energy on performance, fillet composition, feed cost, and physiological responses of pirarucu (Arapaima gigas) juveniles during the grow-out phase in a net cage system. In an on-farm trial for 90 days 225 pirarucu juveniles with initial weight ± standard deviation of 2025 ± 335 g were fed to apparent satiety with extruded diets containing 37.4 (T-37), 40.8 (T-40), 43.9 (T-43), 45.5 (T-46), and 47.1% (T-49) crude protein (CP), increasing lipid levels, and energy:protein ratio fixed in 10 kcal g-1. Protein and lipid concentrations in the diets influenced the cost, fillet composition, and important physiological aspects of the health maintenance and productive performance of the pirarucu juveniles. Fish fed the T-37 diet had lower concentrations of fat in body cavity, fillet and blood, and had a lower cost associated with feeding. The increase in protein and energy levels in the other diets tested reduced the economic return, did not improve the zootechnical performance and caused physiological changes in the fish.
Journal of entomology and zoology studies, 2018
The objective this study was to find out the protein requirement from Shrimp waste meal for superior growth and survival of juveniles of Pacu under laboratory conditions. Three experimental diets were prepared from Shrimp waste maintaining the crude protein levels at 25, 30 and 35% (treatment T1, T2 and T3). Within an experimental period of 90 days, the control group of fishes attended an average weight of 9.81 ± 0.34g with an intermittent growth of 6.27 ± 0.31g and 8.00 ± 0.05g at the end of 30 days and 60 days. Pacu juveniles in T2 fed with 30% crude protein showed better increment in weight of 10.21 ± 0.46g, 23.00 ± 0.43g and 33.22 ± 0.60g at the end of 30 days, 60 days and 90 days respectively along with increment in total length. A significant difference (P
Effects of stocking density on the performance of juvenile pirarucu (Arapaima gigas) in cages
Aquaculture, 2012
Pirarucu, Arapaima gigas, is a carnivorous freshwater fish that exists along the Amazon Basin. This study investigated the effect of stocking density on growth performance and economic return of pirarucu in cages. Fish were stocked at densities of 10 or 12.5 fish/m 3 in 4.0-m 3 cages installed in Sítios Novos Reservoir (Ceará State, Brazil), with three replicate cages for each density. Fish were fed a formulated diet containing 40% crude protein and 14.2 MJ/kg of feed and cultured for 140 days. The following physicochemical parameters of the water were always at satisfactory levels for fish culture throughout the experiments: water temperatures ranged from 26.3 to 30.2°C, DO 3.2 to 7.7 mg/L, pH 6.9 to 7.7 and transparency 100 to 130 cm. Survival was high and ranged between 100.0% and 94.7 ± 5.0% in cages at 10 and 12.5 fish/m 3 , respectively. Density significantly affected (P b 0.05) final mean weight (2630.4 ± 213.7 and 2138.0 ± 148.2 g) and weight gain (2516.9±202.0 and 2043.1±142.9 g). In contrast, specific growth rate (2.25±0.09 and 2.22±0.06%/day), feed conversion ratio (1.2±0.1 and 1.2±0.2) and production (26.3±2.1 and 25.4±2.6 kg/m 3) were not significantly (P>0.05) affected by stocking density. Economic analysis was emphasized mostly on sales price and pirarucu juveniles and feed costs. The total costs of production were estimated at US$4.52/kg and US$5.31/kg for stocking densities of 10 fish/m 3 and 12.5 fish/m 3 , respectively. At a local market price of US$5.55/kg, the model used suggests that a commercial enterprise can be profitable only for density of 10 fish/m 3. Furthermore, the economic viability of implementing of pirarucu culture in cages was analyzed using profitability indicators such as internal rate of return (IRR), net present value (NPV) and payback period. The high survival, very fast growth and moderated production rates of pirarucu stocked demonstrate that cages are a viable alternative method to standard ponds for the commercial production of pirarucu. The economic indicators appear to be attractive, thus pirarucu cage culture can become a profitable industry.
EFFECT OF FOOD PROCESSING ON THE DEVELOPMENT OF PACAMÃ FINGERLINGS (Lophiosilurus alexandri)
2013
Although pacama (Lophiosilurus alexandri), a fish species native to Brazil, is suitable for farming, it has been little investigated. The present experiment evaluates the effect of food processing on the performance and survival rate of pacama fingerlings. An experiment in a completely randomized design was carried out with 48 pacama fingerlings aged 45 days and weighing 1.94 ± 0.01 g. Fingerlings were assigned to three treatments with four repetitions. Each aquarium containing four fingerlings was considered one experimental unit. Fingerlings were submitted to feed treatments with 47.5% crude protein processed in bran, micro-pellet, and moist forms. The average final weight and apparent feed conversion were significantly (P<0.01) affected by food processing. Pacama fingerlings that fed on moist food performed the best, such that moist food rather than bran or micro-pellet forms is recommended.
Dietary lysine requirement of juvenile pacu Piaractus mesopotamicus (Holmberg, 1887)
Aquaculture, 2009
Lysine is the reference essential amino acid in fish feeds and usually the most limiting amino acid in feedstuffs. The dietary lysine requirement of juvenile pacu Piaractus mesopotamicus (4.3 g) was determined using five isonitrogenous (32% CP) test diets containing graded levels of lysine (0.9, 1.17, 1.44, 1.69 and 1.96% of dry diet) fed three times a day to four groups of 18 fish for 74 days. Growth, body composition, nutrient retention and hematological parameters of pacu were analyzed. Analysis of variance showed that all growth performance parameters were significantly affected by dietary treatments. The lysine requirements estimated using regression analysis for maximum weight gain and feed efficiency were 1.45 and 1.51% of dry diet, respectively. Nitrogen retention efficiency increased with increasing levels of dietary lysine up to 1.43% (p < 0.05). Whole-body protein increased (p < 0.05) and whole-body lipid decreased (p < 0.05) with increasing dietary lysine level. Thus, the lysine requirement of juvenile pacu was estimated as being 1.4–1.5% of dry diet or 4.4–4.7% of dietary protein.
Journal of the World Aquaculture Society, 2006
We evaluated the effects of casein-based semipurified diets, alone or supplemented with native Peruvian plants, on growth, feed efficiency, and histology of the digestive tract of red pacu, Piaractus brachypomus, juveniles over an 8-wk feeding trial. Three tanks were randomly assigned to one of four casein-gelatin (40:8) diets containing a supplement of 15% wheat meal (control) or an identical level of substitution of three South American native plant as follows: camu-camu fruit (Myrciaria dubia), aguaje fruit (Mauritia flexuosa), or maca tuber meal (Lepidium meyenii). The fish (initial weight, 2.04 6 0.06 g) were fed experimental diets at decreasing feeding rates from 4 to 2.6% of body weight. After 8 weeks of feeding, fish fed a diet supplemented with maca meal showed significantly higher (P , 0.05) weight gain, specific growth rate, protein efficiency ratio (PER), apparent net protein utilization (NPU), and instantaneous feed intake than fish fed other diets. Feed conversion ratio (FCR), PER, and NPU in fish fed the casein-gelatin diet supplemented with maca meal were among the best ever reported in the scientific literature, 0.64 6 0.03, 3.13 6 0.15 and 23.8 6 2.0, respectively. The camu-camu meal had a negative impact on diet palatability and utilization, which resulted in slower growth. The stomach, intestine, pancreas, and pyloric caeca at the start and end of the experiment showed normal differentiation and appearance of cells and tissues. The liver parenchyma showed lipid infiltration and pigment accumulation in all samples at the initiation of the experiment and may be attributed to the period of decreased feed intake prior to the study. At the end of the study, similar histopathologies were recorded in all samples from the control and camu-camu groups. Normal liver histology (polyhedral hepatocytes with centrally located nuclei) was observed in two of three samples from the maca group and all the samples from the group that was fed the aguaje-supplemented diet.