Resources

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.
Description

Designing diets that are primarily soybean meal (SBM) instead of fishmeal will improve the overall sustainability of the aquaculture industry. A diet must provide good growth to the animal to which it is fed, but it should also neutrally or positively impact the ability of the animal to survive disease outbreak. Thus, a soybean-based diet for summer flounder that optimizes both growth and survival during bacterial challenge, would lead to enhanced profitability and sustainability of summer flounder aquaculture. It is well known that excess SBM in diets for fish can lead to intestinal pathologies like enteritis. However, in our previous work, we have demonstrated that SBM actually appears to stimulate the immune system of summer flounder, whereas soy protein concentrate (SPC) does not do so. Thus, it appears that something that is extracted from SBM to produce SPC (the fraction that is commonly referred to as soy molasses) contains one or more compounds that stimulate the immune system in these fish. We have funding from Rhode Island Sea Grant to identify the fractions of soy molasses that stimulate immune function, but it does not include sufficient funding to examine histopathology of the liver and pancreas or the blood chemistry for certain enzymes. USB funding is enabling us to do that work as part of the Sea Grant project. Although this work is directed toward the summer flounder industry, identification of soy molasses components that stimulate fish immune systems could be broadly applicable to other fish species in aquaculture as well. The concept is to use SPC as the main soy component of fish diets as the protein source, but then to add just the right amount of the appropriate soy molasses factor to boost the immune system as well.

Language
English

Author
niversity of Rhode Island - Bengtson
Description

During phase I of this project, in 2009, we identified an optimal diet for the replacement of fish meal (FM) with soy protein concentrate (SPC) and/or soybean meal (SBM) for summer flounder, based on a feeding trial in which six diets were tested. The diets included a FM control, one diet based on a mixture of FM and SBM, one diet based on a mixture of FM and SPC, and three diets based on a mixture of FM, SBM and SPC. Our work for phase 2 in 2010 was to compare the “best” diet (diet 6, all SPC replacement of FM, with no SBM) from that trial with a “standard” commercial diet in a six-month study using a quasi-commercial-scale rearing environment.

While that work was going on, we also had funding from the National Oceanic and Atmospheric Administration National Marine Aquaculture Initiative (NOAA-NMAI) to investigate different levels of FM replacement with SBM, and especially to examine if those levels affected the performance of the fish (summer flounder) in a bacterial challenge, which tests their resistance to disease. To our surprise, the fish survived best in the bacterial challenge after they had been fed the diet with the highest level of SBM (70% replacement of FM with SBM), even though their growth on that diet was significantly worse than that of fish grown on diets with lesser amounts of SBM. This unanticipated result suggested to us that something in SBM (but perhaps lacking in SPC) may serve as an immunostimulant to boost the immune system of fish.

Based on the results of the NOAA-NMAI work, we proposed to USB that we would examine the relationship between levels of FM, SBM and SPC during 2011. The graduate student involved in the project also had some separate funding for another experiment along these lines in early 2011. Our goal in these studies was to try to quantify the relationship between SBM and SPC levels in the diet and the survival of fish in a bacterial challenge. Fish were grown in our standard feeding trial prior to their use in the bacterial challenge, so we were also able to obtain data on survival, growth, and food conversion before they were challenged.

Language
English

Date Published
October 29, 2012

Author
David A. Bengtson, Marta Gomez-Chiarri, Chong M. Lee and Dan Ward
Description

The project, “Long term evaluation of dehulled soybean meal (DHSBM) as fish meal (FM) replacement for flounder (from growing size to commercial size) at the practical fish farm”, is the cooperative research between the United Soybean Board/American Soybean Association/Korea (Say Young Jo, Country Director) and Feeds & Foods Nutrition Research Center (Sungchul C. Bai, Director) attached to the Pukyong National University. The goal of this project was to evaluate the possibility of utilizing of Dehulled Soybean Meal (DHSBM) as a fish meal replacement in flounder reared at the practical fish farm for a whole production period.

The research lasted for about 12 months in Pohang, Korea. Four experiments were : (1) Evaluation of the effect of dehulled soybean meal as fish meal replacement on growth of flounder from grower to market size at the commercial fish farm; (2) Evaluation of water pollution parameters; (3) Economical evaluation; (4) Investigation of the palatability of flesh. The results indicated that dehulled soybean meal could replace up to 30% of fish meal from the growing size to commercial size of flounder with the supplementation of attractant. When considering the pollution degree and economic effect, the formulated feeds based on further researches on the proper replacement levels of dehulled soybean meal in different fish species should be developed in the future.

Language
English

Date Published
September 30, 2004

Author
United States Soybean Export Council