Effects of a novel bacteria meal (FeedKind®) on the physical properties of extrudates

The development of fishmeal (FM) alternatives for feed in aquaculture is essential for sustainable and economic fish farming. A study was undertaken to evaluate the potential of a novel bacteria meal (FeedKind® (FK)) as fishmeal substitute. There are significant differences between fishmeal and FeedKind® in viscosity, water absorption, water-soluble protein, oil absorption and other physicochemical properties, which in turn affects the physical quality of feed. Increasing FK content will enhance the pellet durability (P < 0.05) and the expansion (P < 0.01), and decrease the oil leakage (P < 0.05) of the extruded feed pellets. This indicates that FK can be used as a feasible substitute for FM to improve the physical qualities of low-starch floating extrudates. The optimal lower moisture content (24.3%−24.9%) and temperature (127.6 ℃−136.7 ℃) requirement in extrusion after FM is replaced by FK is conducive to reducing the consumption of water and electric energy in the drying process, which contributes to the low carbon emissions and sustainable production of fish feed.