OPTIMISED PERFORMANCE AND EFFICIENCY IN ABALONE FEED
Extrusion technology of aquafeeds offers a number of benefits when compared to feed manufactured using other methodologies. Extrusion, which is effectively cooking under pressure, moisture and elevated temperatures, creates a highly water stable product. Using an extruded feed for abalone, in combination with modern formulation strategies, results in abalone with superior growth characteristics and reduced feed conversion ratios.
Extrusion gelatinises the starches in the feed, effectively reducing complex carbohydrates to less complex carbohydrates. As abalone diets are largely made up of carbohydrate-rich raw materials, gelatinisation of the starches is of benefit to an herbivorous mollusc as it improves digestibility, making nutrients and the energy component more biologically available. Abalone diets that are not extruded have reduced starch gelatinisation and therefore a lower digestible energy component. Abalone fed non-extruded diets need to consume more to reach the same level of dietary energy intake, thus increasing the feed conversion ratio and the cost of production.
Abalone are grazing molluscs and the time taken to consume feed is slow. It is therefore essential that any feed has a high water stability to maximise the opportunity for abalone to feed, but also to reduce the chance of nutrients leaching. The extrusion process again has specific benefits here, as it creates a pellet with high structural integrity.
This presentation will highlight the ongoing research undertaken by Skretting to further enhance the benefits of extruded abalone feeds.