The sustainable utilization of commercial fishery resources has become an increasingly important priority for the global aquaculture sector. Fishmeal remains the primary protein source in aquafeeds; however, climate change and overharvesting have reduced the availability of traditional fishmeal species. Fishery byproducts can be potentially server as feed ingredients by they vary in quality depending on fish species and byproduct type, and processing methods can substantially affect their nutritional quality and suitability for feed use.
Lake whitefish is a major contributor to the Great Lakes fishery, yet more than 50% of its processing byproducts remain underutilized. The objective of this project was to evaluate the potential of lake whitefish byproducts as aquafeed ingredients. This preliminary study examined how different grinding and dehydration methods influence the nutritional quality of the resulting products. Two grinding methods were tested: meat grinding alone and meat grinding combined with autoclave cooking. Dehydration methods included oven drying at 40 °C and freeze drying. We hypothesized that differences in processing temperature would alter the nutritional quality of the ingredients and that autoclave cooking would improve grinding efficiency. In addition, we explored the feasibility of blending fishery byproducts with an agricultural byproduct (soycake from soy sauce production) to improve processing efficiency and nutrient retention.
Preliminary results showed that autoclave cooking improved grinding efficiency and produced more homogeneous powders but reduced lipid content compared with non-autoclaved products (38.3% vs. 43.6% on a dry-matter basis). Similarly, oven drying resulted in lower lipid content compared with freeze drying (40.0% vs. 43.6%). In contrast, combining fishery byproducts with soycake improved processing efficiency and nutrient retention. These findings suggest an economically viable approach for valorizing both fishery and agricultural byproducts. Further research is needed to fully evaluate the nutritional value and performance of these alternative feed ingredients in aquaculture diets. The outcomes of this research may provide new revenue streams for local fish processors and agricultural processing industries in the Great Lakes region.