Sustainability and food security are critical challenges that require innovative approaches to utilize alternative raw materials effectively. Project BlueGreenFeed explores using land-based raw materials, such as grass and feathers, to produce sustainable protein for aquaculture through mealworm bioconversion. This study aimed to evaluate the acceptance, survival, and growth of mealworms fed on grass and feather-based feed components.

Mealworm cultivation was carried out using experimental feeds derived from grass and feathers alongside standard feed composed of wheat and barley (69% carbohydrates, 14% protein, 4% lipids). The growing cycle of mealworms was 12 weeks, during which mealworm survival rates, weight gain, and feed consumption were monitored. Feed textures and nutritional compositions were analyzed to assess their influence on mealworm acceptance, growth, and composition.

The results demonstrated that while grass and feather-based feeds were effective protein sources, they failed to provide lipids. The texture differences between standard feed and experimental feeds significantly impacted feed acceptance, with the light, powdery texture of grass and feather feeds proving less appealing to mealworms. This led to reduced survival rates and lower weight gain compared to mealworms fed on standard feed. Grass and feathers feed mix, as well as feathers alone, were identified as promising protein sources but lacked sufficient water content for optimal mealworm development.

The study concluded that while grass and feather-based feed components hold promise as sustainable protein sources, further optimization is required to improve feed texture and lipid content to enhance mealworm growth and survival. Additional research is recommended to refine feed formulations and explore complementary lipid sources.

The study was done in collaboration with scientists from SINTEF in Norway, Aarhus University in Denmark, the University of Iceland and Matis in Iceland, and Tallinn University of Technology in Estonia, with the support of Blue Bioeconomy ERA-NET Cofund and its national agencies.