Combining soybean meal with fish meal made from invasive Asian carp produces a more nutritious, sustainable and economical option for feeding some farm-raised fish, according to recent Southern Illinois University research.
Both lab and on-farm feeding trial research, funded by the Illinois soybean checkoff, show species like hybrid striped bass and largemouth bass can effectively digest higher amounts of soybean meal when blended with meal derived from Asian carp.
"The research may solve several challenges for Midwestern fisheries and the aquaculture industry," says Jesse Trushenski, associate professor at SIU's Center for Fisheries Aquaculture and Aquatic Sciences in Carbondale. "The fish diets we studied use meal from Asian carp, an invasive fish that is spreading and disrupting ecosystems in the Mississippi River Basin. Blending carp meal and soybean meal allowed us to use larger amounts of soybean meal. And, these diets offer a local alternative to marine-based fish meal."
Aquaculture, an expanding, protein-hungry industry, needs to develop alternate feed sources, according to Trushenski. The growing scarcity of wild anchovies and sardines increases the costs of marine-based fish meal and impacts ocean ecosystems. Soybean meal is a proven, renewable alternative, but using just soybean meal in place of fish meal affects the growth and health of some carnivorous species.
"Previous SIU research established Asian carp meal as equal to or better than marine-based fish meal in aquaculture diets, and helped set standards for using soybean meal in aquaculture," Trushenski explains. "We took our understanding of protein for carnivorous fish feed a step further by demonstrating synergies between local protein sources – soybeans and invasive fish."
The research trial formulations used 25% soybean meal and 18% Asian carp meal, proteins readily available in the Midwest. A new carp rendering plant in Grafton will boost availability of Asian carp meal, and demonstrates the ripple effect this solution can have on rural economies.
"Cost-effective carp meal is good news for soybean meal demand in aquaculture," says Duane Dahlman, soybean farmer and Illinois Soybean Association director from Marengo. "This SIU research proves the two ingredients can be used together in a nutritious fish feed blend for key species.