Illinois Soybean Association-Supported Aquaculture Research at SIUC

Transcription

1 Illinois Soybean Association-Supported Aquaculture Research at SIUC Project Updates for Trushenski Research Team CHALLENGES AND OPPORTUNITIES IN AQUACULTURE 1 Aquaculture, the rearing of aquatic plants and animals, is the fastest growing agricultural sector worldwide. Currently, half of seafood consumed is farm-raised, and the contribution of aquaculture to global protein demand and food security will continue to increase. In the U.S., aquaculture is important in the private and public sectors. More than 304,000 MT of food fish were raised in the U.S. in 2007, contributing directly to domestic demand for seafood. In 2004, the U.S. Fish and Wildlife Service and state governments reared more than 20,000 MT (equating to 1.75 billion fish) for fishery enhancement and restoration activities. Indirectly, these hatcheries contribute to seafood supply in the U.S. by supporting capture fisheries, many of which would collapse without supplemental stockings. Although domestic aquaculture production is sizable, it is dwarfed by U.S. seafood imports: in 2009, we imported over 431,000 MT of trout, tilapia, and salmon alone. The U.S. ranks 3rd in capture fishery landings, but only 14th in aquaculture production and remains the 2nd largest importer of seafood it is clear that domestic production must grow to fill the widening seafood gap. Regardless of whether fish are raised at a private farm or a public hatchery, they need to eat and aquaculture is constrained by the availability of cost-effective aquafeeds. Traditionally, aquafeeds were comprised largely of fish meals and oils derived from marine fisheries. Rich in protein, energy, and essential nutrients and historically inexpensive, marine feedstuffs were used because of their nutritional value and palatability to farm-raised fish. Unfortunately, the prices of fish meal and oil have grown by 400% over the last 20 years, including a two-fold increase since Rising costs as well as concern for environmental sustainability and human food safety incentivize the search for alternative feedstuffs, but success depends on our ability to understand the interrelationships between feed, fish, and food. Success also depends on aquaculture partnering with other agri-industries to synergize food production worldwide. ABOUT JESSE TRUSHENSKI Dr. Trushenski is an Assistant Professor at Southern Illinois University Carbondale where she heads a research team dedicated to aquaculture nutrition and fish physiology. Her primary interests are alternative feedstuffs, novel feeds and feeding strategies, and understanding the relationship between nutrients and performance of aquatic livestock. She maintains an active record of professional service to the U.S. Aquaculture and American Fisheries Societies, and is currently President of the AFS Fish Culture Section. WHAT S INCLUDED IN THIS PACKET? Attached are summarizes of ISA-funded aquaculture nutrition projects that the Trushenski lab is involved in. These projects address soy lipids and proteins in feeds for marine and freshwater fishes, including experimental and validation studies. 1 This summary is excerpted from Dr. Trushenski s presentation, One fish, two fish, feed fish, food fish meeting nutritional challenges in aquaculture and aquatic natural resources management, given March 22, 2010 as part of the National Coalition for Food and Agricultural Research Capitol Hill Lunch and Learn Seminar Series ( This presentation highlighted the roles of aquaculture in the public and private sectors, identified challenges in fish nutrition and aquafeed formulation, and proposed strategies to strengthen aquaculture and seafood security in the U.S., including stronger linkage with traditional, terrestrial agricultural sectors.

2 SOY PROTEINS Title: INCREASED UTILIZATION OF SOY-DERIVED PROTEIN SOURCES IN AQUACULTURE FEEDS Principal Investigator(s): Jesse Trushenski Duration of Study: August 2008-December 2010 Project Summary: Aquaculture is the single largest consumer of fish meal, and the industry must reduce its reliance on fish meal to maintain economic viability. A wide variety of alternative protein sources have been evaluated in aquaculture feeds, however, success has varied among products and species. Most of the fish meal replacement research has focused on grain products commonly used in other livestock feeds, i.e. corn, wheat, and soybean meals. Soybean meal has not replaced fish meal to the extent that nutritionists had originally hoped. However, soybean meal was initially targeted primarily because of its ready availability and low cost, not necessarily because of its suitability for aquatic livestock. Other soy derivatives, such as soy protein concentrate and soy protein isolate, were not previously considered because at the time they were cost-prohibitive. As the price of fish meal continues to climb, these refined soy proteins are becoming increasingly competitive alternative protein sources. Soy protein concentrate and isolate offer many advantages over soybean meal, i.e. higher protein:carbohydrate ratios, reduced antinutritional factors, etc., and may be better utilized by carnivorous livestock such as hybrid striped bass. Objective(s): 1) Evaluate the extent to which soybean meal may spare fish meal in feeds for hybrid striped bass without impairing production performance. 2) Identify the extent to which a reduced fish meal feed (Objective 1) can be amended by inclusion of soybean protein concentrate to further reduce fish meal. 3) Further reduce or eliminate remaining dietary fish meal (Objective 2) by implementing soybean protein isolate. 4) Identify and address factors that limit the inclusion of soy-derived protein in feeds for hybrid striped bass. Progress Update: This series of feeding trials revealed several key concepts. First, soybean meal can be implemented at very high levels in hybrid striped bass feeds (>65% of the feed), however, complete fish meal replacement reduces growth performance, and even moderate inclusion of soybean meal can negatively impact the resilience and stress tolerance of the fish. While soy protein concentrate and soy protein isolate are nutritionally valuable ingredients, their use in feeds for hybrid striped bass (particularly very young juveniles) is limited by palatability problems. However, we noted that the addition of a feed attractant increased acceptance of refined soy protein-based feeds. Furthermore, the addition of marine-derived or soy-derived phospholipid can restore growth performance and resilience to hybrid striped bass fed soybean meal-based feeds.

3 SOY PROTEINS Title: FISH MEAL REPLACEMENT WITH SOY-DERIVED PROTEINS IN FEEDS FOR COBIA: INFLUENCE OF REPLACEMENT LEVEL AND ATTRACTANT SUPPLEMENTATION Principal Investigator(s): Jesse Trushenski and Michael Schwarz Duration of Study: June 2009 July 2010 Project Summary: To determine the feasibility of partially or totally replacing marine derived protein in cobia feeds, we assessed the production performance of juvenile fish raised on diets containing increasing amounts of soy-derived protein with or without attractant supplementation. Objective(s): 1) Compare the production performance of cobia fed experimental feeds containing fish meal (100% FM), soy protein concentrate and isolate (0% FM), or a blend of these ingredients (50% FM) as the primary protein sources, and 2) Evaluate the effect of adding a betaine-based attractant to the soy protein-based feeds (50% FM + Attractant, 0% FM + Attractant). Progress Updates: After 6 weeks, production performance was significantly impaired within the 0% FM group, though fish fed the 50% FM based feeds performed as well as those fed the 100% FM control feed. Although intake of the soy-based feeds was slightly lower than the control, these differences were not statistically significant, suggesting any effects of FM replacement on feed palatability and acceptance were minor. Thus, inclusion of the attractant did not affect intake, however, specific growth rate (SGR) and feed conversion ratio (FCR) were significantly improved by incorporation of the attractant into the 0% FM formulation. Our data indicate that FM may be partially replaced with soy-derived protein without affecting production performance, but that feed digestibility and/or utilization may be problematic at higher replacement levels. Although attractant supplementation offered little benefit in terms of feed intake, other purported actions of the product (e.g., osmoprotection) may have reduced total metabolic demands, thereby partially attenuating the loss of production performance associated with complete FM replacement.

4 SOY PROTEINS Title: TESTING CONSUMER ACCEPTABILITY AND NUTRITIONAL VALUE OF HYBRID STRIPED BASS RAISED ON SOY-BASED FEED Principal Investigator(s): Sylvia Smith and Jesse Trushenski Duration of Study: January 2010 March 2010 Project Summary: Hybrid striped bass are a lean, mild-flavored, and versatile product, and are equally popular with culinary professionals and home cooks. Unfortunately, like many other high-value cultured fish, hybrid striped bass are carnivores, and their feeds contain considerable amounts of fish meal and fish oil to meet nutritional requirements and maximize production performance. Fish meal and fish oil are costly, linked with the accumulation of environmental contaminants in farm-raised seafood, and, at current use patterns, not a sustainable source of raw materials for the growing aquaculture industry. As a result, the aquaculture and aquafeed industries are looking for more sustainable alternatives to marine-derived feedstuffs. With support from the Illinois Soybean Association, Dr. Trushenski s research team has been investigating soy-maximized aquafeeds for hybrid striped bass. These studies are generating information that is being used to reformulate and refine feeds to maximize environmental and economic sustainability for the hybrid striped bass industry in Illinois and elsewhere. Although a soy-maximized formulation is coming together at an experimental scale, these diets have not been validated at a commercial production scale. Further, the acceptability of hybrid striped bass reared on soy-based feeds has not been assessed. Our study will address both of these issues, and increase awareness of farm-raised hybrid striped bass among Chicago-area culinary professionals Objective(s): 1) Compare production performance of hybrid striped bass raised to market size on a soymaximized feed vs. a fish meal and oil-based feed in ponds, and 2) Assess the acceptability of these two distinct products in professional culinary setting. Progress Updates: The production trial for this study is ongoing. The fish are currently submarketable (~1 lb.), but will reach a marketable size (~1.5 lbs.) in the Spring of Although final growth performance data is not yet available, after 20 weeks of production, growth performance was equivalent among fish fed the soymaximized and traditional, fish-based feeds. Although the soy-fed fish were slightly smaller (not statistically significant) after 20 weeks, they were leaner than the fish-fed fish; fish raised on the fish-based feeds exhibited excessive fat deposition within the viscera. Football fish are a common problem in hybrid striped bass culture, and seafood brokers are reluctant to purchase fat fish with low dress-out yields. If the soy-based feeds yield leaner fish, with lower visceral weights, the fish will be more marketable.

5 SOY OILS Title: IMPLEMENTATION OF TRADITIONAL AND DESIGNER SOY OILS IN AQUACULTURE FEEDS Principal Investigator(s): Jesse Trushenski Duration of Study: January 2009-December 2011 Project Summary: Nutritional and medical communities have recommended increasing human consumption of long-chain polyunsaturated fatty acids (LC-PUFA). Seafood remains the most effective means of incorporating these nutrients into our diet. Cultured fish can be an excellent source of LC-PUFA, however, use of alternative lipids in aquafeeds can reduce the level of LC-PUFA in the fillet. Using fish oil fish oil-based finishing feeds, fillet LC-PUFA content can be restored to fish that have been raised on alternative lipid-based grow-out feeds. Finishing strategies hold great promise to balance the need for high LC-PUFA-content seafood in the American diet with the need to reduce aquaculture s reliance on fish oil. Three taxa were selected hybrid striped bass, rainbow trout, and Nile tilapia to use as models in conducting the aforementioned research. Completion of the proposed objectives will delineate means to reduce aquaculture s reliance on marine-derived resources while maintaining the nutritional value of cultured seafood. Identification of soy-derived lipid sources that are suitable substitutes for fish oil may reduce aquafeed costs and increase and diversify utilization of traditional and designer soybean oil throughout the aquafeed industry. Objective(s): 1) To assess traditional, high saturated fatty acid, low alpha-linolenic acid, and hydrogenated soy oils as partial substitutes for fish oil in grow-out feeds for hybrid striped bass, rainbow trout, and Nile tilapia. 2) Employing the ideal soy oil identified in Objective #1, evaluate increasing fish oil replacement rates and determine the responsiveness of hybrid striped bass, rainbow trout, and Nile tilapia fillets to long-chain polyunsaturated fatty acid restoration during finishing. Progress Update: Objective 1 screening trials have been completed for rainbow trout and Nile tilapia, and are currently underway for hybrid striped bass. The completed trials have indicated that feeds based on the high saturated fatty acid content soy oil yield equal production performance, and minimize the effect of fish oil replacement on the loss of beneficial LC-PUFA from the fillet. It is anticipated that the hybrid striped bass trial will yield similar results. Results to-date are encouraging and instructive in that they illustrate the previously unacknowledged value of saturated fatty acid-rich lipids in aquafeeds. By using the saturated fatty acid-rich soy oil in the subsequent finishing trials, it is likely that maximum restoration of fillet quality can be achieved. By understanding the ideal characteristics of fish oil alternatives, i.e., high saturated fatty acid content, feeds can be strategically formulated to contain maximum amounts of soy-derived lipid. Although this project focuses on Nile tilapia, hybrid striped bass, and rainbow trout, we were able to conduct an additional pilot study to evaluate the high saturated fatty acid, low alpha-linolenic acid, and hydrogenated soy oils as partial substitutes for fish oil in largemouth bass feeds. The largemouth bass trial revealed results similar to those we have observed in the other taxa: all of the soy lipids evaluated are suitable for sparing fish oil, but the high saturated fatty acid soy oil is the most advantageous in terms of maintaining beneficial tissue fatty acid profile.

6 SOY OILS Title: EFFECT OF REPLACING DIETARY FISH OIL WITH SOYBEAN OIL ON PRODUCTION PERFORMANCE AND FILLET LIPID AND FATTY ACID COMPOSITION OF JUVENILE COBIA Principal Investigator(s): Jesse Trushenski and Michael Schwarz Duration of Study: June 2009 July 2010 Project Summary: As a marine carnivore exhibiting exceptionally high growth rates, cobia are considered a species for which fish oil replacement may be difficult. However, partial, if not complete, fish oil replacement is necessary to ensure sustainability. We evaluated the effects of graded substitution of dietary fish oil with soybean oil in cobia culture. Objective(s): 1) Compare production performance of cobia raised on feeds containing fish oil (100% fish oil), soybean oil (0% fish oil) or blends of the two (67% fish oil, 33% fish oil) as the supplemental lipid source, and 2) Evaluate the fillet fatty acid composition of cobia fed the diets described for Objective 1. Progress Updates: Production performance was largely unaffected by partial replacement of fish oil with SO: feed intake and final weight were reduced only in the 0% fish oil dietary treatment. Fillet total lipid fatty acid composition differed among the dietary treatments, closely approximating dietary fatty acid profile. As increasing amounts of fish oil were replaced, SO-associated fatty acids became enriched within the fillet lipid at the expense of fish oil-associated fatty acids. Fillet lipid classes were associated with a particular fatty acid signature, regardless of dietary fatty acid profile. SO can replace a substantial amount of dietary fish oil; however, juvenile cobia appear to exhibit a nominal requirement for intact long-chain polyunsaturated fatty acids. Therefore, aggressive fish oil replacement may result in essential fatty acid deficiencies unless the feeds can be amended with alternative sources of these essential nutrients.

7 SOY OILS Title: SOY OILS IN ESSENTIAL FATTY ACID AND LIPID NUTRITION OF COBIA Principal Investigator(s): Jesse Trushenski and Mike Schwarz Duration of Study: January 2010-December 2011 Project Summary: There are relatively few studies which have addressed the specific nutrient requirements of cobia in a quantitative manner. Although studies have been conducted to determine the ideal amount of lipid to include in cobia rations, essential fatty acid requirements have not been directly investigated. Although there is some information available regarding estimated combined requirements, fish oil replacement in cobia feeds will be limited until the individual requirements for DHA and EPA are quantitatively determined. Once the DHA and EPA requirements are determined, nutritionists can formulate diets accordingly and accurately assess the suitability of alternative lipids. Without this critical information, investigations of lipid nutrition will be continue to be hampered by the confounding effects of essential fatty acid deficiency on the interpretation of results. Fish oil replacement studies in other species are similarly limited if the minimum dietary requirements for DHA and EPA are not known, it is impossible to clearly determine whether an alternative oil-based diet is problematic because of its fatty acid composition or some other characteristic. Furthermore, without this information, it is impossible to determine how a formulation might be amended to make it successful in yielding acceptable production performance. Objective(s): 1) Determine the DHA and EPA requirements of cobia fed soy oil-based feed formulations. 2) Providing DHA and/or EPA supplements to meet the dietary requirements identified in Objective #1, evaluate various soy-derived lipids as alternatives to fish oil in cobia feeds and the impact of phospholipid supplementation on utilization of these fish oil alternatives. Progress Updates: The feeding trial for Objective #1 is complete. Althoughconfirmatory tissue analysis is ongoing, production performance data indicate that while DHA is crucially essential for cobia, EPA is largely dispensable. Fish grew as well on soy-oil based feeds as they did on fish oil-based feeds, so long as the diet was supplemented with sufficient amounts of DHA. This breakthrough will allow for much more aggressive fish oil replacement in the formulation of cobia feeds.

8 PUBLICATIONS Fish Meal Replacement with Soy-derived Protein in Feeds for Juvenile Cobia: Influence of Replacement Level and Attractant Supplementation Jesse Trushenski1*, Michael Schwarz 2, Jérôme Laporte 1, Heidi Lewis 1, Brendan Delbos 2, Ricardo Takeuchi 3, Luís A. Sampaio Fisheries and Illinois Aquaculture Center, Southern Illinois University Carbondale, Carbondale, IL 62901, USA Virginia Seafood Agricultural Research and Extension Center, Virginia Tech, Hampton, VA 23669, USA International Initiative for Sustainable and Biosecure Aquafarming, Norfolk, VA 23503, USA Marine Fish Culture Laboratory, Institute of Oceanography, Federal University of Rio Grande, Rio Grande, RS, , Brazil *Corresponding author: saluski@siu.edu, Running Title: Cobia Fish Meal Replacement Key Words: fish meal replacement, soy protein concentrate, soy protein isolate, betaine, attractant Abstract To determine the feasibility of replacing fish meal in cobia feeds, we assessed the production performance of juveniles fed diets containing increasing amounts of soy-derived protein with or without attractant supplementation. Feeds (~50% protein, ~10% lipid) contained fish meal (100% FM), soy protein concentrate and isolate (0% FM), or a blend of these ingredients (50% FM); two additional feeds contained a betaine-based IN PRESS conversion ratio were improved by incorporation of the attractant into the 0% FM formulation. Our data attractant (50% FM + Attractant, 0% FM + Attractant). Production performance was significantly impaired within the 0% FM group. Although intake of the soy-based feeds was slightly lower than the control, these differences were not significant, suggesting any effects of FM replacement on feed palatability and acceptance were minor. Thus, inclusion of the attractant did not affect intake, however, specific growth rate and feed indicate that FM may be partially replaced with soy-derived protein without affecting production performance, but that digestibility and/or utilization may be problematic at higher replacement levels. Although attractant supplementation offered little benefit in terms of feed intake, other purported actions of the product may have reduced total metabolic demands, thereby partially attenuating the effects associated with complete FM replacement.

9 PUBLICATIONS

10 PUBLICATIONS Growth performance and tissue fatty acid composition of rainbow trout reared on feeds containing fish oil or equal blends of fish oil and traditional or novel alternative lipids Jesse Trushenski*, Patrick Blaufuss, Bonnie Mulligan, and Jérôme Laporte Fisheries and Illinois Aquaculture Center and Department of Zoology Southern Illinois University Carbondale Carbondale, Illinois USA Voice: 618/ Fax: 618/ Running Title: Novel Lipids in Rainbow Trout Feeds Key Words: fish oil replacement, soybean, canola, rapeseed, cottonseed, palm, coconut, low linolenic oils, Oncorhynchus mykiss, fatty acid, saturated fatty acid, long-chain polyunsaturated fatty acid Abstract Fish oil sparing is common in aquafeed formulation, however, some alternative lipids have proven more successful than others in ensuring adequate growth and maintenance of desirable fillet fatty acid (FA) composition. Depending on the lipids used, grow-out feeds influence the FA composition of the tissues of lean-fleshed fishes and their responsiveness to subsequent tailoring during finishing. To address whether different lipid sources similarly influence growth performance and tissue composition of a fat-fleshed fish, we fed rainbow trout Oncorhynchus mykiss feeds containing fish oil (FISH), or a 50:50 blend of fish and coconut (COCONUT), palm (PALM), standard soybean (STD-SBO), hydrogenated soybean (HYD-SBO), low 18:3n-3 soybean (LO-ALA-SBO), or low 18:3n-3 canola (LO- IN PRESS ALA-CAN) oils. Two saturated FA (SFA) enriched lipids derived from cottonseed (SFA-COT) and soybean (SFA-SBO) processing were also evaluated as 50% fish oil substitutes. After 7 weeks, growth performance was largely unaffected by dietary lipid source. Fillet levels of long-chain polyunsaturated FA (LC-PUFA)among fish fed the HYD-SBO, LO-ALA-SBO, SFA-SBO, and SFA-COT feeds were equivalent to those fed the FISH feed, despite a ~50% reduction in dietary LC-PUFA intake. Our results indicate feeds containing a blend of fish oil and novel soy- or cottonseed-derived lipids yield equivalent growth performance and fillet LC-PUFA content in rainbow trout. Although feeding standard soybean, coconut, palm, or modified canola oils did not impair growth or efficiency, use of these lipids altered fillet FA profile. Rainbow trout appear to differ somewhat from other fishes in terms of dietary influence on tissue FA profile, however, a pattern of greater LC-PUFA retention among fish fed SFA-rich feeds appears to be largely consistent among those fishes we have assessed.

11 PUBLICATIONS

12 PUBLICATIONS