The search for novel ingredients remains a top priority in the aquafeed industry. This drive is fuelled by the well-described and judicious use of ingredients of marine origin, geopolitical matters, and, more recently, the environmental footprint and credentials associated with these ingredients. In Australia, th ere is an increasing focus o n reducing the reliance on imported ingredients, particularly those with a substantial environmental footprint. T he CSIRO aquaculture nutrition research group has evaluated a series of novel ingredients , namely, microbial biomass, mussel by-product meal, insect meals, food waste meals, speciality soybean meals, novel canola meals and concentrates, and fermented plant meals in feeds for several prawn and fish species , in the context of in-vitro bioactivity essays, digestibility studies, and growth trials. Careful validation of novel ingredients is paramount to derisking their use for the development of sustainable aquafeed.
Preliminary in-vitro results indicate that insect and mussel by-product meals exhibit anti-inflammatory properties that were superior to the levels in comparison to fishmeal and other ingredients. I n in-vivo trials, mussel by-product meal was well accepted by prawns and enhanced production performance parameters. In terms of juvenile barramundi, food waste streams showed to be a promising source of novel nutrients for aquafeed. Diets based on multiple streams of food waste were not only well-accepted but also supported satisfactory growth performance. Blending multiple food waste streams proved to be a successful approach when utilising highly diverse nutrient sources. The development of canola products, including protein concentrates, showed great promise for use in aquafeeds. Juvenile salmon and prawn effectively utilised these ingredients compared to traditional canola meal and soybean meals. Fermentation of plant meals is another strategy which delivered promising results and was dependent on feed management. The complementary feeding of fermented plant-based feeds via dual-feeding strategies (replacing up to 50% of the commercial feed) achieved performance equivalent to the control treatment fed 100% of the commercial diet in prawn s and low trophic fish. In contrast, s peciality soybean genotypes developed to have reduced or undetectable amounts of lipoxygenases, altered glycinin profile, and reduced levels of oligosaccharides did not confer any growth and gut health benefits to juvenile salmon when added at high dietary inclusion levels compared to the traditional soybean meal.
Some of these test ingredients are already commercially available, while others are still under development, with the viability of upscaled production yet to be evaluated. Collectively, these findings illustrate the potential and nutrition feasibility of integrating novel ingredients into aquafeeds. The associated c hallenges and future perspectives will be discussed in detail during the presentation.