Carvalho R.A.P.L.F.D.,University of Sao Paulo |
Carvalho R.A.P.L.F.D.,Federal University of Rio Grande do Norte |
Ota R.H.,University of Sao Paulo |
Kadry V.O.,University of Sao Paulo |
And 3 more authors.
Aquaculture | Year: 2016
The apparent digestibility coefficients (ADC) of six practical protein ingredients, Chilean fish meal (FM), soy protein concentrate (SPC), poultry by-product meal (PBM), corn gluten meal (CGM), meat and bone meal (MBM), and hydrolyzed feather meal (HFM), were determined for juvenile white shrimp (Litopenaeus vannamei) at dietary inclusion levels of 10, 20 and 30% within a reference diet containing 20% fish meal. The shrimp was stocked in 500 L tanks equipped with automatic feeders and settling columns for solids collection in a recirculating system. The highest growth rates were observed for the shrimp fed with the test diets with FM and SPC, from the 30% to 10% inclusion levels, followed by the byproducts HFM, MBM, PBM and CGM, from the 10% to 30% inclusion levels. The effects of the protein sources and inclusion levels on the apparent digestibility coefficients of ingredients were more pronounced than in the test diets. The calculated ADC of the test ingredients were significantly affected by the ingredient type and inclusion level, with the exception for the protein ADC. The highest apparent digestibility coefficients of the ingredients were recorded for FM, SPC, PBM and MBM at the 20% inclusion level and CGM at the 30% inclusion level. The apparent amino acid digestibility (AAAD) recorded for the ingredients were different from previously reported values for the L. vannamei. The in vivo method for digestibility determination is subjected to different factors affecting its accuracy. Further studies should aim to improve the precision and produce reliable data to support feed formulation, nutrient assimilation, and aquatic animal performance. Statement of relevance Knowledge about the nutritional value of ingredients for shrimp diets is needed. This paper introduces new information about the digestibility of commercial feedstuffs given at different levels, in a practical diet. Shrimp were reared in a RAS using specifically designed tanks, with performance comparable to shrimp farms. Effects of the method on the reliability of digestibility data are also discussed. © 2016 Elsevier B.V.
De Carvalho R.A.P.L.F.,University of Sao Paulo |
Lemos D.E.L.,University of Sao Paulo |
Tacon A.G.J.,Autonomous University of Baja California |
Tacon A.G.J.,Aquatic Farms Ltd.
Aquacultural Engineering | Year: 2013
In vivo digestibility determination in shrimp is a challenge because these animals are coprophagous, benthic and slow feeders and the small amount of feces that they produce is difficult to collect. The objective of this study was to evaluate an efficient tank design for the purpose of studying shrimp digestibility. Different tank designs were evaluated considering drain system (dual-drain and single-drain), water inlet flow rate (8, 12, and 16Lmin-1) and bottom drain diameter (6, 13, 19, 25 and 50mm) and their effects on tank hydraulics, water velocity and solids flushing. A circular and slightly conical 500L tank was adapted with a clarifier for the two dual-drain designs (Cornell-type and central-type) and settling columns for the two single-drain designs (Guelph-F and Guelph-L). Results showed that: (1) water rotational velocity profile was more homogeneous in tanks with larger bottom drain outlets, and water velocity increased with water inlet flow rate from almost zero up to 14.5±0.7cms-1; (2) solids flushing, measured as the percentage of feed pellets retained at both the bottom drain and in the settling devices, was positively correlated with the surface loading rate (Lmin-1 flow per m2) and was more effective at the Guelph-L design fitted with a 150mm diameter settling column. In this system 100% of the solids were removed at the inflow rate of 16Lmin-1. It can be concluded that among the systems evaluated, the Guelph-L at an inflow-rate of 12Lmin-1 was most efficient for both solids removal and water velocity profile and thus seemed more suitable for shrimp digestibility studies in high performance conditions. Technologies involving hydrodynamic must be intensively applied to solids removal for aquatic species production as well as research purposes like digestibility, which is highlighted in this study. © 2013 Elsevier B.V.
Effects of different protein and carbohydrate contents on growth and survival of juveniles of Southern Chilean freshwater crayfish, Samastacus spinifrons [Efecto de diferentes niveles de proteína y carbohidratos sobre el crecimiento y sobrevivencia de juveniles del camarón de río del sur de Chile, Samastacus spinifrons]
Salgado-Leu I.,Catholic University of Temuco |
Tacon L.G.,Aquatic Farms Ltd.
Latin American Journal of Aquatic Research | Year: 2015
In cultivated aquatic organisms nutritional requirements are critical, not only for their impact on production techniques, but also, for their high incidence on production costs. There is limited knowledge on some species such as the southern Chilean freshwater crayfish, Samastacus spinifrons. In order to generate practical knowledge, a study was carried out to determine protein and carbohydrate content requirements. These factors were evaluated upon their effects on growth and survival of juveniles. For this purpose, individual weight, biomass gain, survival, and feed conversion parameters were measured. The assay was carried out in 42 days, it was conducted in a flow through system, using 21 plastic tanks of 10.6 L capacity. Each tank was seeded with 20 juveniles weighing 50 mg average each. A 3x2 factorial design was proposed with three protein contents (20, 30, 40%) and two carbohydrate contents (low: from 16.3 to 23.5% and high: from 34.6 to 35.8%). Six treatments and three replicates were performed. Individuals were fed on apparent satiation once a day. The diets formulated with 30% of protein and the two carbohydrate contents resulted in higher biomass increases, food conversion efficiencies over 26%, and specific growth rate of 0.78%, all displaying significant differences. Survival showed highly significant differences; in all diets were superior to 60%, however the diets with 30% of protein surpassed 90%. © 2015, Escuela de Ciencias del Mar. All rights reserved.
Daly E.A.,Oregon State University |
Benkwitt C.E.,Aquatic Farms Ltd. |
Brodeur R.D.,National Oceanic and Atmospheric Administration |
Litz M.N.C.,Oregon State University |
Copeman L.A.,Oregon State University
Marine Biology | Year: 2010
Juvenile salmon exhibit high growth rates upon their arrival into the marine environment. Dietary changes from freshwater and estuarine habitats to those derived from the marine environment may play an important role in ultimate adult survival. We measured the total lipid and fatty acid (FA) composition of juvenile Chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), and 18 of their potential prey items sampled from coastal waters during their first few months at sea. Coho salmon had significant reductions in their lipid content (% wet weight) between May and June, likely due to early marine growth. We did not find a significant drop between May and June Chinook salmon lipid content, which may indicate an earlier ontogenetic selection to marine prey that are higher in lipids and essential fatty acids (EFAs). Juvenile salmon ate prey of both high and low lipids. Significant FA compositional changes occurred for both coho and Chinook salmon between May and June. In May, the FA profile of juvenile salmon, especially coho salmon, did not resemble their prey items; however, in June, there was a strong correlation between salmon and their common fish prey as determined by gut content analysis. Significant increases in the level of EFAs, especially docosahexaenoic acid (DHA, 22:6n-3) accounted for the majority of the monthly differences in salmon tissue FA composition. In order for juvenile salmon to adequately meet their physiological requirements, they may have adapted to select advantageous prey with higher levels of EFAs, especially DHA, in order to rapidly increase their growth and ultimate survival. © 2010 Springer-Verlag.
Tacon A.G.J.,Aquatic Farms Ltd. |
Metian M.,International Atomic Energy Agency
Reviews in Fisheries Science and Aquaculture | Year: 2015
The rise of aquaculture has attracted a great deal of attention and this has increased since the sector is now providing more fish and crustaceans than capture fisheries. This global prominence has been partly facilitated by the availability and onfarm provision of feed inputs within the major aquaculture producing countries. More than 70% of the total global aquaculture production is dependent upon the supply of external feed inputs. For the aquaculture sector to maintain its current growth rate, the supply of nutrient and feed inputs will have to grow at a similar rate, while aquatic ingredients production remains static and other sectors compete for same feed resources. This paper attempts to make a global analysis of aquaculture growth, its role in global food production, and to update the estimates of compound feed dependent fish and crustacean species. Copyright © Taylor & Francis Group, LLC.
Chowdhury M.A.K.,University of Guelph |
Tacon A.G.J.,Aquatic Farms Ltd. |
Bureau D.P.,University of Guelph
Aquaculture | Year: 2012
Digestibility trials were carried out to determine the apparent digestibility of amino acids (AA) of two novel plant protein ingredients, Indian mustard protein concentrate-(IMC, 62% crude protein) and Indian mustard meal (IMM, 42% crude protein) produced through a low temperature process, and a commercially available soy protein concentrate (SPC, 57% crude protein) in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). The apparent digestibility coefficient (ADC) of crude protein (CP) from IMC was 90% and 97% for trout and salmon, respectively. The ADCs of CP from IMM and SPC were also very high (> 95%) for both species. The ADCs of lysine (95%), isoleucine (91%), leucine (86%) and phenylalanine (90%) from IMC were slightly lower (P< 0.05) than those from IMM and SPC for rainbow trout. Conversely, for Atlantic salmon, ADCs of isoleucine from both IMC (94%) and IMM (92%) were lower than those from SPC (97%). Despite small differences, the ADC of most AA in these novel products were very good (> 90%). These results suggest that low glucosinolate Indian mustard protein concentrate and Indian mustard meal are ingredients of high nutritive value. However, it is hypothesized that the high phytic acid level in the Indian mustard protein concentrate may negatively affect the digestibility of CP and certain amino acids when used at high level in the feed of fast growing fish. © 2012 Elsevier B.V.
Nance S.L.,Aquatic Farms Ltd. |
Riederer M.,University of Washington |
Zubkowski T.,Northwest Atlantic Fisheries Center |
Trudel M.,Northwest Atlantic Fisheries Center |
Rhodes L.D.,National Oceanic and Atmospheric Administration
Diseases of Aquatic Organisms | Year: 2010
Although there are a variety of methods available for the detection of Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmon and trout, the enzymelinked immunosorbent assay (ELISA) is probably the most widely used method. However, ELISA measures bacterial antigen, which does not necessarily reflect the number of cells present. We hypothesized that dual analysis of kidney tissue by ELISA and a quantitative real-time polymerase chain reaction assay (qPCR) would provide complementary information about antigen level and the number of bacterial genomes. We found that DNA extracted from the insoluble fraction of the ELISA tissue preparation produced the same qPCR result as DNA extracted directly from frozen tissue, permitting true dual analysis of the same tissue sample. We examined kidney tissue in this manner from individual free-ranging juvenile Chinook salmon and antibiotic-treated captive subadult Chinook salmon and observed 3 different patterns of results. Among the majority of fish, there was a strong correlation between the ELISA value and the qPCR value. However, subsets of fish exhibited either low ELISA values with elevated qPCR values or higher ELISA values with very low qPCR values. These observations suggest a conceptual model that allows inferences about the state of infection of individual fish based on dual ELISA/qPCR results. Although this model requires further assessment through experimental infections and treatments, it may have utility in broodstock selection programs that currently apply egg-culling practices based on ELISA alone. © Inter-Research 2010.
Aquatic Farms Ltd. | Date: 2016-12-28
Aquatic Farms Ltd. | Date: 2016-12-28
Aquaponics kits for home and commercial use to grow plants and fish.