Enhanced Resource Utilization of Distiller's Grains: Cascade Conversion Via Black Soldier Fly and Yellow Mealworm for the Production of High - Quality Insect - Derived Feed Protein

Abstract

The development of novel feed protein resources is of utmost significance for the sustainable growth of animal husbandry, particularly in China. In recent years, the biotransformation of organic waste into alternative proteins through the use of insects has garnered widespread attention. China generates a substantial amount of distiller's grains, which possess great potential for further exploration in feed applications. However, distiller's grains, being characterized by high humidity and perishability, face challenges in resource utilization. To tackle this problem, this study developed a graded processing approach. Black soldier fly larvae, which are more adaptable to high - moisture substrates, were initially utilized to convert the organic matter in fresh distiller's grains. Subsequently, yellow mealworms were employed to degrade cellulose and other substances, with the goal of enhancing the resource utilization of distiller's grains. During this cascade conversion process, remarkable findings were observed. The content of cellulose, hemicellulose, and lignin decreased by 28.41%, 48.06%, and 34.65% respectively. The dry matter reduction rate of distiller's grains reached 32.55%, while the biological conversion rates of black soldier fly larvae and yellow mealworms were 7.75% and 1.19% respectively. In this study, for every 300 g of fresh distiller's grains processed via the cascade biotransformation technology, 9.387 g of biomass from the two species of larvae and 70.005 g of dry distiller's grains residue were obtained. This research highlights the potential of a novel cascade conversion model. This model can efficiently transform distiller's grains and other high - fiber materials into insect biomass, which represents a highly promising new source of protein and energy.

Keywords: Distiller's grains, Black soldier fly, Yellow mealworm, Biotransformation，Animal protein