Performance of Juvenile Yellow Perch (Perca flavescens) Fed Diets Containing Upgraded Dried Distillers Grains

Aquaculture relies heavily on marine-derived fish meal (FM) as a primary feed ingredient.  Industry growth, high demand, and increasing cost of finite FM supplies creates urgency to find alternative protein sources. Plant products having sufficient nutrient composition, no anti-nutritional factors, and provide comparable fish performance offer a viable alternative.  With additional processing, current grain ethanol product streams may increase the utility of these coproducts as feed ingredients. This study investigated the performance of juvenile Yellow Perch fed diets containing dry distiller’s grains coproducts, modified by a mechanical or fermentation process, compared to a FM-based control diet.  Growth performance and organosomatic indices were assessed after a 16-week feeding trial. One fermented product and one mechanically concentrated DDG with solubles (DDGS) had the highest survival (90%). The FM control resulted in the highest relative growth (443.5%), while two fermented DDGS treatments demonstrated similar performance. Specific growth was significantly different (p<0.0001) among treatments with FM performing better than the modified diets. Organosomatic indices were similar across treatments. Fillet to body weight ratio was highest for fish fed two mechanically concentrated products. These results show improvement over previous studies using unmodified coproducts, but continued research focused on upgrading coproducts is necessary to improve performance.