Effect of Inclusion of Tenebrio molitor and Aquaculture By-products on the Physico-chemical Properties of Whiteleg Shrimp (Penaeus vannamei) Aquafeeds

Due to the limitations associated with fishmeal, including high cost, limited availability, and sustainability concerns, the aquaculture industry has been driven to seek alternative ingredients for feed formulation. Although these ingredients are usually characterised by taking into account their nutritional composition, it is also essential to understand the technological properties that they may exhibit during feed processing and pellet manufacture. In this study, different aquafeeds with partial and total replacement of fishmeal were evaluated. These diets were formulated using Tenebrio molitor meal (T-50 and T-100), crustacean by-product mixtures (Mix1-50 and Mix1-100), and fishery by-product mixtures (Mix2-50 and Mix2-100), and were compared to a control diet based on fishmeal (CT). Both the proximate composition (protein, lipid, ash, and moisture content) and several physical properties of the pellets were analysed, including bulk density, water stability, floatability, and durability. The results show that diets containing by-product mixtures significantly increased mineral content, as reflected by a higher ash level that exceeded 9%. Regarding the physical properties, the feeds containing T. molitor meal exhibited density and stability values similar to those of the CT, approximately 670 g/L and 82% stability. In contrast, the Mix1 diets produced pellets with low density (less than 660 g/L) and high porosity, although their structural resistance was not affected. Furthermore, all feeds were sinking pellets and displayed high durability values above 99%. In conclusion, the partial or total replacement of fishmeal with Tenebrio molitor meal and different by-products is technically feasible, as it does not affect the physical properties of pellets while still contributing to the development of more sustainable aquaculture feed formulations.