Will Hehemann | School of Agriculture, Fisheries and Human Sciences
Yathish Ramena, a doctoral candidate of aquaculture/fisheries at the University of Arkansas at Pine Bluff, and visiting scientist at the USDA/Agricultural Research Service (ARS) – Harry K. Dupree Stuttgart National Aquaculture Research Center, recently completed a study that examined non-genetically modified (GMO) soybean meal as a healthy and cost-effective substitute for fish meal in the diets of hybrid striped bass.
“The production of hybrid striped bass is an expanding aquaculture industry across the nation,” Ramena said. “As carnivorous fish, striped bass require a higher amount of protein in their diet. However, the price of fish meal has drastically increased in the last 20 years, from $450 to $2,300 per ton.”
Soybean meal is thought of as the best alternative to fish meal, as it has a dense protein profile, he said. Currently, most of the soybeans produced in the U.S. are genetically altered for higher production and disease resistance.
“In some fish, conventional soy products have been shown to cause adverse effects on growth and health performance that are linked to anti-nutritional factors (ANFs) in the processed soybean meal,” Ramena said. “These effects include lower digestibility and nutrient absorption rates.”
Ramena’s research focused on whether the use of traditionally bred soybeans reduces the negative impacts on hybrid striped bass. He used non-GMO soy varieties produced by the University of Arkansas at Fayetteville, which were specifically bred to contain fewer ANFs. Genetically modified (GMO) soybeans can also be produced to contain fewer ANFs, but negative perceptions of GMO-based feeds have stimulated more research on conventionally bred soybean varieties for use in the diets of farmed animals, he said.
Digestibility trials indicated that hybrid striped bass fed with non-GMO soybean meal had a significantly higher rate of protein absorption than fish fed other meals. In the growth trial, Ramena replaced 100 percent fish meal with 100 percent non-GMO soybean meal.
The results were positive, Ramena said. Not only were the fish as healthy as fish fed with regular fish meal, but they also had higher immune capabilities for survival in unfavorable conditions.
This research provides new insight into the effects of improved strains of soybeans for bass diets,” Dr. Rebecca Lochmann, interim chair of the UAPB Department of Aquaculture and Fisheries and Ramena’s research advisor, said. “Bass are not vegetarians, so the ability to use cheaper plant meals in diets instead of fish meal while maintaining fish growth and health is a significant economic advance.”
Dr. Steve Rawles, Ramena’s USDA/ARS project mentor, said, “There is a lot of interest in increasing the use of soy products in carnivorous fish diets. Mr. Ramena’s work is an important contribution to that endeavor.”
Dr. Muthusamy Manoharan, interim assistant dean for research & Extension, UAPB School of Agriculture, Fisheries & Human Sciences, said the potential use of non-GMO soybeans in the diets of carnivorous fish adds to the industry’s sustainability.