Resources

Description

Salmonids (primarily Atlantic salmon and rainbow trout) are the most cultured family of carnivorous fishes in the world, with 2004 production values of approximately two million metric tonnes (mmt) valued at US $6.5 billion (FAO 2006). The salmonid industry accounts for approximately 3% of total global aquacultural production, but its value is nearly 10% of total global aquacultural value (FAO 2006). Over the past ten years, the industry has more than doubled production output. Norway and Chile are the two primary producing countries, accounting for approximately 60% of global salmonid production (FAO 2006).

Commercial feed formulations for salmonids currently incorporate 30 to 45% fish meal (New and Wijkstroem 2002). Global fish meal production typically ranges between 6-7 mmt annually (FAO 2006). The salmonid industry is utilizing about one third of the total amount of fish meal used in aquaculture feeds (Hardy 2002). However, recent declines in the harvest of fishes utilized to produce fish meal (primarily in Peru) lead to an historic high of $1,600 per metric tonne of fish meal in the summer of 2006 (Hardy 2006). As fish meal prices climb, production costs for salmonid farmers increase as well (New and Wijkstroem 2002). Additionally, as fish farmers increase production, the economic return per unit of production decreases. For Atlantic salmon, the return per unit has decreased by 20-40% since 1986-1987 (FAO 2006). If the salmonid industry is going to continue to grow, alternative proteins will need to be incorporated into their feed formulations.

As the salmonid industry incorporates changes to their feed formulations, they need to assure that these changes have a minimal impact on fillet quality. Salmonid fillets are an excellent source of high quality protein. In addition, they contain high amounts of the n- 3 fatty acids eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Farmed salmonids contain slightly higher levels of EPA and DHA than wild harvested salmonids, with farmed rainbow trout containing 1.15 g EPA and DHA per 100 g serving, compared to 0.99 g EPA and DHA per 100 g serving of wild caught rainbow trout. Farmed Atlantic salmon contain 2.15 g EPA and DHA per 100 g serving, compared to 1.80 g EPA and DHA per 100 g serving of wild caught Atlantic salmon (all values are cooked edible portion) (USDA/ARS 2006). The Food and Drug Administration (FDA) and American Heart Association (AHA) recommend two meals (one meal is 170.1-226.8 g) of fish per week, especially fatty species such as salmonids, to maintain a healthy lifestyle. In 2004, the FDA allowed a qualified health claim for reduced risk of coronary heart disease on conventional foods that contain EPA and DHA (FDA 2004). As the salmonid feed industry transitions to alternative protein and lipid sources, EPA and DHA levels in the diet and fillet will need to be considered.

Soybean meal (SBM) is an alternative protein ingredient currently of great interest to the aquaculture industry. In 2005, global production of soybean seeds was estimated at 218 mmt, but more importantly, global production of SBM was estimated to be 145 mmt, more than 20 times greater than the average global production of fish meal (USDA 2006). SBM prices can vary, but typically cost around US $200 per metric tonne (www.aquafeed.com). Dehulled SBM contains approximately 48% crude protein, one of the highest protein contents of all plant-based protein ingredients (NRC 1993). When used as a primary protein source, the essential amino acid profile of SBM, with the exception of methionine, is adequate to meet the known requirements of salmonids (NRC 1993).

Despite the global availability and nutritional characteristics of SBM, it has not been incorporated into salmonid diets at high inclusion rates. SBM is typically incorporated at 10-30% of the diet depending on species and feed manufacturer (Hardy 2002; Pillay and Kutty 2005). The relatively high concentration of carbohydrates and presence of antinutritional factors (ANF) are believed to be the primary factors limiting the amount of SBM used in salmonid feeds (Francis et al. 2001; Hardy 2002). Lectins, oligosaccharides, saponins and trypsin inhibitors are all present in SBM and have the ability to act as ANF when fed to fish. Soy isoflavones (also called phytoestrogens) may also exert negative effects when fed to fish by exerting estrogenic effects; however, isoflavones may also have a beneficial effect by acting as an antioxidant. Researchers have attempted to identify the specific components of SBM that are limiting its use in salmonid diets; however, most of this research evaluated SBM that had been subjected to various extraction techniques that removed several potential ANF instead of evaluating purified ANF derived from SBM (Francis et al. 2001). Consequently, the specific antinutritive compounds present in SBM that are exerting negative effects on salmonids have not been identified

In 2002, the United Soybean Board (USB) and the Indiana, Illinois and Ohio State Boards funded the Soy-in-Aquaculture (SIA) Managed Aquaculture Program. SIA was established to overcome the barriers limiting the amount of soy ingredients in aquaculture feeds. The initial SIA initiative contained two separate but related programs. The goal of the first component focused on increasing the amount of soy inclusion in feeds used by well-established, intensive aquaculture industries that were underutilizing soy in their feed formulations. Specific objectives were to systematically evaluate specific ANF and determine which ones were causing problems when fed to salmonids. This research was conducted at seven institutions, led by Purdue University (West Lafayette, IN, USA). The second program was international marketing led by the American Soybean Association/United States Soybean Export Council. The primary objective of that program was to increase usage of soy-based formulations by fish farmers in Southeast Asia and India. The remainder of this document will focus on the research portion of the SIA initiative.

Language
English

Author
Steven D. Hart (Purdue University), Frederic T. Barrows (Agricultural Research Service, Hagerman Fish Culture Experiment Station), Konrad Dabrowski (Ohio State University), Siddhartha Dasgupta (Kentucky State University), Donald L. Garling (Michigan State
Description

The United Soybean Board’s Soy-in-Aquaculture(SM) Managed Research Program (SIA) and Archer Daniels Midland Company (ADM), announce a collaborative effort to establish a new soybean meal (SBM) nutrient database designed to help feed formulators use SBM in diets fed to aquatic animals. This collaborative effort marks the first full nutrient and anti-nutritional factor (ANF) characterization of SBM in aquatic animal diets. This characterization is important considering the fact that ANF levels in SBM vary significantly depending on various factors such as cultivar.

Language
English

Author
United States Soybean Export Council
Description

World aquaculture production is dominated by omnivorous fish species that live in freshwater, including various carp and catfish species. Soybean meal is a prominent ingredient used in prepared diets for these species, often constituting 50 to 60% of the total formulation. Such levels of incorporation are possible due to adequate palatability of soybean meal and its excellent nutritional value for these species, including high levels of crude protein, complementary amino acid profile and relatively high nutrient digestibility. For many omnivorous freshwater species cultured throughout the world, soybean meal has largely replaced more costly protein feedstuffs in diet formulations, such as fish meal, while maintaining optimal fish production. As a result, the cost of fish production has been reduced substantially. While aquacultural production continues to expand worldwide to meet the growing demand for seafood, the use of soybean products will play an even more important role in providing high-quality protein for various fish species.

Language
English

Author
Delbert M. Gatlin III
Description

Atlantic salmon, Pacific salmon and rainbow trout, collectively known as salmonids, are the most farmed carnivorous fish species in the world, mainly because they are prized food fish and relatively easy to culture. Salmon and trout can survive in a variety of environmental conditions, such as water temperatures from 0oC to as high as 28oC for some trout strains. They spawn successfully in water temperatures from 2oC to 15oC, and grow at temperatures from 6oC to 25oC. Depending upon their diet, salmon and trout can have pigmented (red) or non-pigmented (white) flesh. Salmon and trout are sometimes thought of as freshwater fish and other times as marine fish, but they are very adaptable to a variety of saline conditions.

Language
English

Author
Ronald W. Hardy
Description

The United Soybean Board’s Soy-in-Aquaculture(SM) Managed Research Program (SIA) and Archer Daniels Midland Company (ADM), announce a collaborative effort to establish a new soybean meal (SBM) nutrient database designed to help feed formulators use SBM in diets fed to aquatic animals. This collaborative effort marks the first full nutrient and anti-nutritional factor (ANF) characterization of SBM in aquatic animal diets. This characterization is important considering the fact that ANF levels in SBM vary significantly depending on various factors such as cultivar.

Language
English

Author
United States Soybean Export Council
Description

As marine ingredient levels are reduced in aquafeed, supplementation with low levels of taurine may be required to optimize production. Taurine may not only improve growth and performance, but also is required to reduce nutritional diseases such as green liver disease and low hematocrit levels in some fish. Taurine is authorized for fish feed in all species in the European Union and China, but not the United States.

Language
English

Author
M. Rhodes, W. Rossi, Jr., T. Hanson, Ph.D., D. Allen Davis, Ph.D.
Language
English

Date Published
October 24, 2016

Author
Soy Aquaculture Alliance
Language
English

Date Published
October 24, 2016

Author
United States Soybean Export Council
Description

A cooperative feeding demonstration was conducted in 2013 between USSEC and Titikaka Trout Co. in Lake Titicaca, Puno, Peru. The objective of the demonstration was to show the feasibility of using a U.S. manufactured soy protein concentrate (NutrivanceTM) to replace fishmeal in the diet for cage cultured rainbow trout Oncorhynchus mykiss. NutrivanceTM is a feed grade soy protein concentrate (SPC) with high protein and low oligosaccharide content and minimal soy anti-nutritional factors. Rainbow trout performance was compared with a NutrivanceTM SPC diet and a fishmeal based diet. Results yielded similar trout performance with the two diets. The demonstration confirmed that SPC can partially replace fishmeal in the diet for rainbow trout, and that NutrivanceTM SPC is an acceptable ingredient for use in trout diets, thereby providing an alternative to fishmeal for the Peruvian trout farming industry.

Language
English

Date Published
October 25, 2013

Author
Jairo Amezquita, Mark Newman, Jorge Valencia, Dr. Herbert E. Quintero
Description

Aquacultural production of trout and salmon, collectively referred to as salmonids, is one of the largest global aquaculture industries and currently uses a disproportionately high amount of fish meal in dietary formulations. Sustainable production and growth in salmonid culture demands identification of alternative high-protein feed ingredients. The chemical composition of soy protein concentrate (SPC) suggests it has potential has an ingredient in diets fed to salmonids. There have been over 30 published studies of SPC use in diets for rainbow trout and Atlantic salmon. The data indicate small trout and salmon are more sensitive to SPC inclusion in diets than larger fish. SPC can provide up to 50% of the dietary crude protein in diets for small fish. Fish meal can be completely replaced in diets for larger fish. Results from digestibility studies indicate high nutrient availability from SPC. Methionine supplementation appears necessary for salmonids and taurine supplementation was recently identified as beneficial in SPC-based diets for trout. The form of phosphorus in SPC remains problematic, but incorporation of phytase or pretreatment of SPC with phytase improved phosphorus availability. Sensory characteristics of salmonid fillets fed SPC have been lighter in color than those from fish fed fish meal, but texture and flavor have not been adversely impacted. Several dietary formulations are available that have been tested in the target species. Ingredient cost hampered use of SPC in the 1990’s and remains an issue in the 21st century. However, given the escalating price of fish meal and demand for that commodity, use of SPC in salmonid diets appears promising.

Language
English

Date Published
October 29, 2011

Author
United States Soybean Export Council
Description

Salmonids (primarily Atlantic salmon and rainbow trout) are the most cultured family of carnivorous fishes in the world, with 2004 production values of approximately two nmillion metric tonnes (mmt) valued at US $6.5 billion (FAO 2006). The salmonid industry accounts for approximately 3% of total global aquacultural production, but its value is nearly 10% of total global aquacultural value (FAO 2006). Over the past ten years, the industry has more than doubled production output. Norway and Chile are the two primary producing countries, accounting for approximately 60% of global salmonid production (FAO 2006).

Commercial feed formulations for salmonids currently incorporate 30 to 45% fish meal (New and Wijkstroem 2002). Global fish meal production typically ranges between 6-7 mmt annually (FAO 2006). The salmonid industry is utilizing about one third of the total amount of fish meal used in aquaculture feeds (Hardy 2002). However, recent declines in the harvest of fishes utilized to produce fish meal (primarily in Peru) lead to an historic high of $1,600 per metric tonne of fish meal in the summer of 2006 (Hardy 2006). As fish meal prices climb, production costs for salmonid farmers increase as well (New and Wijkstroem 2002). Additionally, as fish farmers increase production, the economic return per unit of production decreases. For Atlantic salmon, the return per unit has decreased by 20-40% since 1986-1987 (FAO 2006). If the salmonid industry is going to continue to grow, alternative proteins will need to be incorporated into their feed formulations.

As the salmonid industry incorporates changes to their feed formulations, they need to assure that these changes have a minimal impact on fillet quality. Salmonid fillets are an excellent source of high quality protein. In addition, they contain high amounts of the n- 3 fatty acids eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Farmed salmonids contain slightly higher levels of EPA and DHA than wild harvested salmonids, with farmed rainbow trout containing 1.15 g EPA and DHA per 100 g serving, compared to 0.99 g EPA and DHA per 100 g serving of wild caught rainbow trout. Farmed Atlantic salmon contain 2.15 g EPA and DHA per 100 g serving, compared to 1.80 g EPA and DHA per 100 g serving of wild caught Atlantic salmon (all values are cooked edible portion) (USDA/ARS 2006). The Food and Drug Administration (FDA) and American Heart Association (AHA) recommend two meals (one meal is 170.1-226.8 g) of fish per week, especially fatty species such as salmonids, to maintain a healthy lifestyle. In 2004, the FDA allowed a qualified health claim for reduced risk of coronary heart disease on conventional foods that contain EPA and DHA (FDA 2004). As the salmonid feed industry transitions to alternative protein and lipid sources, EPA and DHA levels in the diet and fillet will need to be considered.

Soybean meal (SBM) is an alternative protein ingredient currently of great interest to the aquaculture industry. In 2005, global production of soybean seeds was estimated at 218 mmt, but more importantly, global production of SBM was estimated to be 145 mmt, more than 20 times greater than the average global production of fish meal (USDA 2006). SBM prices can vary, but typically cost around US $200 per metric tonne (www.aquafeed.com). Dehulled SBM contains approximately 48% crude protein, one of the highest protein contents of all plant-based protein ingredients (NRC 1993). When used as a primary protein source, the essential amino acid profile of SBM, with the exception of methionine, is adequate to meet the known requirements of salmonids (NRC 1993).

Despite the global availability and nutritional characteristics of SBM, it has not been incorporated into salmonid diets at high inclusion rates. SBM is typically incorporated at 10-30% of the diet depending on species and feed manufacturer (Hardy 2002; Pillay and Kutty 2005). The relatively high concentration of carbohydrates and presence of antinutritional factors (ANF) are believed to be the primary factors limiting the amount of SBM used in salmonid feeds (Francis et al. 2001; Hardy 2002). Lectins, oligosaccharides, saponins and trypsin inhibitors are all present in SBM and have the ability to act as ANF when fed to fish. Soy isoflavones (also called phytoestrogens) may also exert negative effects when fed to fish by exerting estrogenic effects; however, isoflavones may also have a beneficial effect by acting as an antioxidant. Researchers have attempted to identify the specific components of SBM that are limiting its use in salmonid diets; however, most of this research evaluated SBM that had been subjected to various extraction techniques that removed several potential ANF instead of evaluating purified ANF derived from SBM (Francis et al. 2001). Consequently, the specific antinutritive compounds present in SBM that are exerting negative effects on salmonids have not been identified.

In 2002, the United Soybean Board (USB) and the Indiana, Illinois and Ohio State Boards funded the Soy-in-Aquaculture (SIA) Managed Aquaculture Program. SIA was established to overcome the barriers limiting the amount of soy ingredients in aquaculture feeds. The initial SIA initiative contained two separate but related programs. The goal of the first component focused on increasing the amount of soy inclusion in feeds used by well-established, intensive aquaculture industries that were underutilizing soy in their feed formulations. Specific objectives were to systematically evaluate specific ANF and determine which ones were causing problems when fed to salmonids. This research was conducted at seven institutions, led by Purdue University (West Lafayette, IN, USA). The second program was international marketing led by the American Soybean Association/United States Soybean Export Council. The primary objective of that program was to increase usage of soy-based formulations by fish farmers in Southeast Asia and India. The remainder of this document will focus on the research portion of the SIA initiative.

Language
English

Date Published
October 29, 2006

Author
Steven D. Hart (Purdue University), Frederic T. Barrows (Agricultural Research Service, Hagerman Fish Culture Experiment Station), Konrad Dabrowski (Ohio State University), Siddhartha Dasgupta (Kentucky State University), Donald L. Garling (Michigan State)
Description

Increasingly, plant protein sources including soybeans are being evaluated as replacements for fish meal in the diets of farmed carnivorous fish. Many plant protein sources contain factors that can exert nutritional and antinutritional effects in fish, and alter other developmental processes including reproduction.

Genistein is an isoflavone that is found in significant concentrations in soybeans. Genistein can have both estrogenic and antiestrogenic effects, either of which, in turn, can have stimulatory or suppressive actions on growth and reproduction in fish. The purpose of this study was to assess the effects of genistein on the growth, development and reproduction of rainbow trout and Atlantic salmon, to clearly elucidate the potential positive and negative effects of this isoflavone before large-scale attempts are made to incorporate increasing amounts of soybean products into commercial salmonid diets.

In rainbow trout, for a one year period fish were fed diets containing genistein at four concentrations: 0 (control), 500, 1,000 and 3,000 ppm. At all doses tested, genistein had no effect on growth or feed conversion. Serum levels of vitellogenin, measured at four times during the treatment period, were higher in genistein-treated fish (all doses) than controls. We found no effects of genistein on serum levels of reproductive hormones, morphology and histology of the gonads (both sexes), egg production, fertility rates, fry size nor viability. Accordingly, we suggest that the genistein content of soy products should not be a factor in determining their incorporation into the diets of rainbow trout.

In Atlantic salmon parr, for a six-month period fish were fed diets containing genistein at four concentrations: 0 (control), 500, 1,000 and 3,000 ppm, and a fifth group of fish were fed estradiol-17β (E2) at 20 ppm as a positive control. At all doses tested, genistein had no effect on growth or feed conversion. At the end of the treatment period, serum levels of vitellogenin were higher in the E2 and genistein treated fish than in controls. E2 and genistein at all doses tested inhibited the process of smoltification, as measured by 24-hr seawater challenge tests. Accordingly, the incorporation of genistein into the diets of Atlantic salmon parr may be contraindicated.

We suggest that further studies be conducted to evaluate the effect of genistein on Atlantic salmon smolts, to determine the appropriateness of high soybean meal content on Atlantic salmon grow-out diets.

Language
English

Date Published
October 29, 2005

Author
Jeffrey A. Malison*, Luciene C. Lima, Yuliana, Terence P. Barry and James A. Held
Description

The Soy-in-Aquaculture Managed Research Program is working to determine the chemicals in soybean meal that can limit the greater use of soy meal in feeds for varied aquaculture species. Initial work with the salmonid industry found problems related to soy lectins and trypsin inhibitors, but determined benefits from saponins and isoflavones.

Language
English

Date Published
October 29, 2005

Author
Steven Hart Paul Brown, Ph.D.
Description

The overall objective of our portion of the collaborative soybean study is to evaluate the quality of market sized rainbow trout and salmon reared on diets containing significant levels of soybean meal as a primary protein ingredient. In year 2, we completed the following: 1) quality evaluation of rainbow trout reared on experimental genistein-containing diets for 12 months, and 2) quality evaluation of rainbow trout reared on soy-containing diets.

Language
English

Date Published
October 29, 2004

Author
Denise Skonberg and Natasha D’Souza
Description

A feeding trial was completed several quarters ago in which diets containing high quantities of soybean meal were subjected to extreme processing conditions during pelleting, using a Buhler Twin-Screw Extruder (DNDL 44). Three processing variables were studied: (1) pre-conditioning or no pre-conditioning; (2) extruder barrel temperature (low or high); and (3) time during which the feed mixture was in the barrel (short or long). Various combinations of processing conditions were employed to produce rainbow trout feeds, which were subsequently used in a 12-week feeding trial to evaluate the effects of processing conditions on the nutritional value of the diets for the trout. These results have been reported, and initial diet analysis has been completed, but an error in feed sample handling in our laboratory made it impossible to conduct analysis for protein dispersibility index (PDI) and trypsin inhibitor activity (TIA). Activity and accomplishments during the quarter

1. Experimental diets used for the rainbow trout growth study were re-manufactured using the same equipment, ingredients, and processing conditions as were used to produce diets for the rainbow trout feeding trial. Samples of these diets were analyzed again for proximate composition and energy content to ensure that they were essentially identical to earlier diets. Diet samples are currently being analyzed for PDI and TIA, with analysis scheduled for completion early next quarter.

2. Rainbow trout were fed control and high-soybean meal diets (40%) for six months to produce market-sized trout (>500g). These fish were killed, gutted, chilled, and sent by overnight courier to the Dr. Denise Skonberg, University of Maine, for sensory and nutrient analysis. Twenty fish from each dietary treatment group were sent.

Work planned for next quarter
1. Complete PDI and TIA analysis on feed samples and complete report on feeding trial.

2. Begin feeding trial with rainbow trout fed high-soybean meal diets supplemented with various volatile fractions of fish meal production to determine if they affect intake. Previous work on another project demonstrated that partial hydrolysis of fish meal increased intake of high-soy diets by rainbow trout.

Language
English

Date Published
October 29, 2004

Author
Ronald W. Hardy1 and Frederic T. Barrows2