Soybean Meal Replacement of Fish Meal – As a result of increasing demand, uncertain availability, and increasing cost for fish meal (FM), fish nutritionists have been driven to find alternative sources of protein. Particularly for carnivorous species such as Yellow Perch (Perca flavescens (Mitchell), alternative plant-based feedstuffs have shown decreased performance compared to FM. Processed (mechanical, chemical, or microbiological) soybean products are of primary interest as alternative feedstuffs due to their availability, domestic production, low price and nutritional profile; however, use of processed soy has displayed varying degrees of success. Novel soy ingredients created through bioprocessing technology potentially provide more highly digestible nutrients with fewer anti-nutritional factors (ANFs) than traditionally processed soy products.

To examine the utility of certain bioprocessing technologies, ingredient compositions were compared and incorporated into three Yellow Perch feeding trials. The first feeding trial was completed to measure apparent digestibility of protein and energy of commercial and experimental bioprocessed soybean meal (BP-SBM), and other common feed protein ingredients. Bioprocessing consistently upgraded the bioavailability of protein in defatted soybean meal, while commercially bioprocessed xvi Hamlet HP 300 provided the highest digestibility of all soy products tested. Extrusion as a pretreatment to bioprocessing had a negative effect on digestibility.

The second experiment was a 14-week feeding trial to evaluate growth performance, digestibility, and organosomatic responses of Yellow Perch fed diets containing commercial alcohol-washed soy protein concentrate (SPC), bioprocessed soy white flake (BP-WF), or extrusion pretreated BP-WF as complete FM replacements. Each soy protein source was replicated in diets with and without supplemental lysine + methionine. BP diets consistently performed better than SPC diets. Extrusion pretreatment led to improved consumption and growth performance over unextruded products. Lysine and methionine supplementation further improved growth. SPC diets provided the best feed conversion ratio (1.62) and highest apparent digestibility of protein (91.8%), but examination of anatomical characteristics revealed significant deficiencies in fish fed SPC diets.

In the final 16-week feeding trial they evaluated growth performance, feed intake, and organosomatic responses of Yellow Perch fed diets containing various processed SBM products. Treatment factors included soybean variety (GMO or non-GMO), extrusion pretreatment and FM replacement levels (40 and 70%). An FM control and 14 soy-based diets were formulated on a dry matter basis to contain similar crude protein (45%), lipid (9%), and gross energy (20.9 MJ/Kg). Five soy treatments displayed higher relative growth than the FM control diet and nine lower growth. A non-GMO, nonextruded, extruded SBM provided enhanced growth at both inclusion levels when compared to FM. Both the GMO and non-GMO commercial SBMs provided similar growth to the reference diet at the low FM replacement level, but growth was depressed at the higher level.

Scott C. Sindelar. 2014. Utilization of soybean products as fish meal protein replacement in yellow perch (Perca flavescens) feeds. A thesis submitted in partial fulfillment of the requirements for the Master of Science Major in Wildlife and Fisheries Sciences Specialization in Fisheries Sciences South Dakota State University.

An 8-week feeding trial was conducted to evaluate the effects of replacing fish meal with soybean meal (SBM) on growth, feed utilization, and nitrogen (N) and phosphorus (P) excretion of juvenile Pseudobagrus ussuriensis (a genus of bagrid catfish inhabiting streams and rivers in eastern Asia). Juveniles weighting about 0.5 gram were allocated to seven isonitrogenous and isolipidic diets formulated with SBM replacing fish meal protein at 0%, 10%, 20%, 30%, 40%, 50% and 60%. One additional diet was formulated to determine whether 0.30% crystalline methionine added to the 60% replacement diet would improve growth.

The results showed that there was no significant difference in weight gain among fish fed diets containing up to 40% SBM, however, a significant reduction in this weight gain occurred when 50% and 60% of fish meal protein was replaced by SBM (P ‹ 0.05). Apparent digestibility coefficients of dry matter, crude protein and phosphorus of diets were affected by dietary SBM levels; fish meal replacement by SBM resulted in an increase in N excretion and a reduction in P excretion. Adding crystalline methionine to the 60% fish meal replacement diet did not improve growth, feed utilization and N and P excretion. The results of this study show that 40% of fish meal protein could be replaced by SBM in diets of juvenile P. ussuriensis without having a significant negative effect on growth or feed efficiency, but that higher dietary SBM levels reduce fish performance.