Feeding rate for pacu reared in net cages (original) (raw)
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.
In the present study, wild caught early fingerlings Milkfish (Chanos chanosForsskål, 1755) (length & weight between of 3.8-6.4cm / 3-8g) average weight 5.35g werereared with different types of treatments for three months(15thNovember-15th February) and their performances in terms of growth and survival were determined. It is observed that upon the harvest the fish reached a weight between24-31g and a survival rate of 80.1±1%,thespecific growth rate was higher (82.8%) in fishes gatheredin the combination of soil & chicken manure (SC), followed bya combination of Urea & chicken manure (UC), and commercial pellets(CP) Control feeds. Survival rate was also higher in SC fishes, followed by UC and CP (control)feed. The size-frequency distribution shows that milkfish in the tank SC grew compared with tank CP specimens, their growth rate was lower. Tanks containing SC treatment had better specific growth rate than CP (control) treatment (p<0.05), although there was no significant differences between SC treatment and UC treatment in growth factors. Also, the number of surviving fish in UC treatment was simply higher than SC treatment and CP (control) (p<0.05). Key Words:Milkfish, Chanos chanos, growth, fingerling
Aquaculture, 2015
The present study evaluated the effects of different fasting periods on survival rate, growth, muscle development and compensatory growth in pacu (Piaractus mesopotamicus) larvae. In Phase I, larvae (5 days post hatching, dph) reared under an intensive system in laboratory conditions were subjected to 0, 2, 4, 6 or 8 days fasting followed by 10 days of regular feeding with live feed. In Phase II, the same larvae were transferred to outdoor ponds, in a semi-intensive system, where post-fasting growth was investigated for 30 days. After fasting, larvae exhibited weight reduction, loss of muscle mass and smaller-diameter fibers, but after they were regularly fed for 10 days, growth performance and morphometric analysis of muscle fibers showed that muscle mass and weight were recovered. At the end of the Phase II, juvenile survival was higher in fish subjected to 0 (control) and 2 days fasting than those subjected to 4 days fasting. With respect to the distribution of juveniles into size classes, those subjected to 4-day fasting yielded a higher proportion (63%) of super small-size individuals, whereas most juveniles from 0-to 2-day fast treatments were medium-sized. In short, pacu larvae under different fasting periods are capable of compensatory growth, and if fasting does not exceed 2 days, subsequent growth performance and muscle development are not affected. This short fasting regime can therefore serve as an emergency feeding strategy to produce juveniles of this important South American fish species.
Journal of the World Aquaculture Society, 2009
To facilitate economical culture of black pacu, Colossoma macropomum, and red pacu, Piaractus brachypomus, in the Amazon region of South America, we assessed locally available alternative energy sources for practical diets. We tested the effects of control diets (containing wheat products) versus diets with different Amazonian feedstuffs (yucca, Manihot sculenta, plantain, Musa paradisiaca, or pijuayo, Bactris gasipaes) on the performance of the pacus in three feeding trials. Black pacu (22.5 6 0.03 g; Trial 1) or red pacu (2.56 6 0.01 g; Trial 2) were fed diets containing 30% wheat bran (control) or cooked or uncooked yucca, plantain, or pijuayo for 12 wk. In Trial 3, larger black pacu (86.9 6 6.4 g) were grown to market size in 24 wk on similar diets. Weight gain, feed conversion, survival, alternative complement activity, and lysozyme were similar among diets. Hepatosomatic index, liver glycogen, and dry matter were affected by diet in Trials 1 and 2, but effects were not consistent among trials. In Trial 3, protein efficiency ratio was lower in fish fed the diet containing wheat middlings. However, relative to wheat bran or wheat middlings, all feedstuffs tested were effective energy sources for juvenile black pacu and red pacu. Black pacu, Colossoma macropomum, and red pacu, Piaractus brachypomus, are highvalue species cultured for human consumption in Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela. The black pacu has also been introduced to Costa Rica, Cuba, Mexico, and Panama (Campos-Baca and Kohler 2005). Natural supplies of these fish cannot meet market demand, and aquaculture production is intensifying. Practical diet formulations for these species are evolving. Their natural diets are rich in plant products (Kubitzki and Ziburski 1993; Araujo-Lima and Goulding 1997), and many Amazonian plant feedstuffs may be suitable for inclusion in practical diets for characids. Some native ingredients have been used in feeds produced on farm, but there is little research on their efficacy as feedstuffs compared to more typical products such as wheat. Although wheat is one of the chief sources of energy in formulated diets for characid fish, it is not traditionally cultured in the Amazonian region and must be imported at a premium price. In contrast, yucca, Manihot sculenta, pijuayo, Bactris gasipaes, and plantain, Musa paradisiaca, are often grown
Risk Management in Aquaculture by Controlled Feeding Regimen
Pakistan Journal of Nutrition, 2003
Fish nutrition researchers often feed fishes at between 3-5% of their body weight daily. Environmental risks associated with excess feed leachate are so enormous in tropical waters leading to algal bloom which can toxify the aquaculture products and threaten their safety. Considering that feed requirements by fishes depend on a number of factors such as size, health status and the general condition of the culture environment; there is every need for the determination of the actual feed desired to meet their physiological needs, promote growth and reproduction based on peculiar conditions. This study was conducted to determine the appropriate feeding rate for tilapia, Oreochromis niloticus and consequential changes in the water quality. A 30% crude protein diet was fed to triplicate groups of O. niloticus fingerlings (10.13±0.58g) in glass tanks (75x45x40 cm) (20 fish/tank) at 2, 3, 4 and 5% body weight daily. The holding tanks were cleaned every two days after measuring the water quality parameters, pH, temperature and the dissolved oxygen. Results of the experiment indicated that the weight gain (WG, %) and specific growth rate (SGR) of the fishes fed at 3, 4 and 5% body weights were similar (p>0.05) but differed significantly (p<0.05) from the WG and SGR of the group of fishes fed at 2% body weight. However, there were no significant differences in FCR and PER of fishes fed at the various body weights. While the pH and the temperature of the culture media were not affected by the treatments, the dissolved oxygen was marginally lower in tanks fed at 4 and 5% body weights than in those fed at 2 and 3% body weights. The study established the optimum feeding rate for O. niloticus at 3% body weight daily, and the tendency for water quality deterioration with higher feeding rates.