Skretting made one of the first advances in the 1980s by introducing extruded feeds. The next increase came with vacuum coating. Jan Jonkers, Feed Production Manager at the Skretting Aquaculture Research Centre (ARC), explained that this involves a vacuum chamber that follows the drying stage, the vacuum draws the oil into the feed pellets instead of just coating them.
Jonkers added that this formulation has lifted fat levels above 30 percent because reducing pressure opens pores in the pellets to absorb more oil. Alternatively, accurate control of pressure can deliver feeds with sinking characteristics optimised to customer requirements, says Jonkers. It is fact that high fat feeds brought two new challenges. The first was how to keep the fat in the feed in warm weather.
Skretting overcame this challenge through the development of SPAR technology, which involves adding a small proportion of a particular ingredient to the mix. This forms crystals that block the pores and trap the oil inside the pellets. The second challenge is the sustainability of the oil supply. Aquaculture was expanding rapidly and the far sighted foresaw a potential scarcity of the fish oils being used.
Dr Alex Obach, Managing Director at Skretting ARC, said that ARC is one of the participants in the EU-funded RAFOA project. This project had the objective of replacing as much fish oil as possible without compromising the health, welfare and growth performance of the four main European aquaculture species: Atlantic salmon, trout, sea bass and sea bream. The next sustainability objective was to reduce fishmeal contents. This was achieved by introducing vegetable proteins.
