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United States Department of Agriculture

Agricultural Research Service

Research Project: INTEGRATION OF NUTRITIONAL, GENETIC AND PHYSIOLOGICAL APPROACHES TO IMPROVE PRODUCTION EFFICIENCY OF RAINBOW TROUT Title: Processing soybean meal for biodiesel production; effect of a new processing method on growth performance of rainbow trout, Oncorhynchus mykiss

Authors
item Barrows, Frederic
item Gaylord, Thomas
item Sealey, Wendy - UNIV OF ID, HAGERMAN, ID
item Haas, Michael
item Stroup, Robert - STROUP ASSOC. INC.

Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 29, 2008
Publication Date: July 3, 2008
Repository URL: http://riley.nal.usda.gov/nal_web/digi/submission.html
Citation: Barrows, F., Gaylord, T.G., Sealey, W.M., Haas, M.J., Stroup, R.L. 2008. Processing soybean meal for biodiesel production; effect of a new processing method on growth performance of rainbow trout, Oncorhynchus mykiss. Aquaculture.283:143-147.

Interpretive Summary: Standard soybean meal is produced by toasting to reduce trypsin inhibitor levels and hexane extraction to remove the valuable soybean oil. The extracted oil is used primarily in human foods, with its use as a feedstock for production of biodiesel growing rapidly. A new method of soybean meal processing has been developed, which may simplify the process of biodiesel production. This method, ‘in situ transesterification’, eliminates hexane extraction to remove the oil, combining the extraction and transesterification steps so as to synthesize biodiesel via a single treatment conducted directly on a lipid-bearing solid material. If the resulting meal is comparable in nutritional value to commercially available hexane extracted soybean meal (SE-SBM) the new process could become widely used in the bio-fuel industry. Two levels (17.5 and 35%) of each of three types of soybean meal were fed to triplicate lots of rainbow trout. The three types of soybean meal included SE-SBM, experimentally produced hexane extracted SE-SBM (ESE-SBM), and meal produced using in situ transesterfication (IS-SBM). There was no effect of source of soybean meal on weight gain of trout. The fish fed the meal processed by the new method, IS-SBM, gained as much weight as fish fed either of the two control meals, within an inclusion level. The fish fed the diets containing IS-SBM, however, did have higher feed intakes (2.51% bw/d) as compared to fish fed the ESE-SBM or SE-SBM, 2.38 and 2.46% bw/d, respectively. Protein and energy retention values were lower for the fish fed the IS-SBM diets. ADC for protein was lower for the IS-SBM (85.9%) than for the ESE-SBM (89.3%). Feeding IS-SBM did not decrease weight gain in this study, but due to the increased feed intake and FCR, long term feeding trials should be conducted to further evaluate the meal.

Technical Abstract: Standard soybean meal is produced by toasting to reduce trypsin inhibitor levels and hexane extraction to remove the valuable soybean oil. The extracted oil is used primarily in human foods, with its use as a feedstock for production of biodiesel growing rapidly. A new method of soybean meal processing has been developed, ‘in situ transesterification’, which eliminates hexane extraction to remove the oil and combines the extraction and transesterification steps so as to synthesize biodiesel via a single treatment conducted directly on a lipid-bearing solid material. Two levels (17.5 and 35%) of each of three types of soybean meal were fed to triplicate lots of 30 (initial wt 22g.) rainbow trout for 9 weeks in flow-through 15 °C spring water. The three types of soybean meal included solvent extracted soybean meal (SE-SBM), experimentally produced hexane extracted SE-SBM (ESE-SBM), and meal produced using in situ transesterfication (IS-SBM) and were each fed at two levels for a total of 6 diets. There was no effect of source of soybean meal on weight gain of trout. The fish fed the meal processed by the new method, IS-SBM, gained as much weight as fish fed either of the two control meals, within an inclusion level. The fish fed the diets containing IS-SBM, however, did have higher feed intakes (2.51% bw/d) as compared to fish fed the ESE-SBM or SE-SBM, 2.38 and 2.46% bw/d, respectively. Protein and energy retention values were lower for the fish fed the IS-SBM diets. There was no effect of soybean source on carcass composition. ADC for protein was lower for the IS-SBM (85.9%) than for the ESE-SBM (89.3%). Feeding IS-SBM did not decrease weight gain in this study, but due to the increased feed intake and FCR, long term feeding trials should be conducted to further evaluate the meal.

Last Modified: 11/24/2014
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