Web-based tech offers insight on RAS feeding
Researchers from Portugal-based SPAROS presented findings from a RAS feeding experiment at Aquaculture Europe 2020 on April 14. The study used Feednetics, a web-based application that uses a mechanistic nutrient-based model to predict fish growth and composition over time based on temperature, feed intake and feed properties.
The study compared two high-energy trout feeds, including one designed for RAS. The study found the RAS feed led to an 11 per cent shorter production cycle, improved FCR by 0.1 units and a decrease in total nitrogen (-12 per cent) and phosphorus (-25 per cent) wastes, explained Ana Nobre, SPAROS product manager and environmental engineer.
Based on Feednetics results, the decrease in the average water temperature affects the non-RAS feed proportionally more. The total phosphorus waste increases about 29 per cent when decreased by two degrees celsius.
“With the high energy feed, the production cycle (to grow fish from 50g to 1kg) increases by 35 days under the low temperature profile. At 13 C, the total production time considering the two feeds lag by about one month, with the RAS feed representing savings of around €82 per ton of fish,” said Nobre.