To assess the potential to increase feed efficiency in Atlantic salmon by genomics and selective breeding, activities are merged from the two Horizon 2020 EU-projects AquaIMPACT and NewTechAqua and an internal Nofima project. This work is done in collaboration between the Atlantic salmon breeding company MOWI Genetics and the research institute Nofima.
Why is feed efficiency a key trait for sustainability?
Fish that are feed efficient require less feed to reach market size, and they better direct energy towards lean and fillet growth as opposed to excessive fat reserves which are a costly slaughter waste. Feed comprises ~50 percent of the total production costs and ~80% of the carbon footprint of Atlantic salmon farming. Any increase in feed efficiency results in large reductions in the total production costs and improves the sustainability for this large European aquaculture sector.
Recording of feed intake is a challenge
Unlike in terrestrial animals, it is very challenging to record how much feed an individual fish consumes in a day. Instead, it is far more simple to record how much feed is consumed by a group of fish in a tank.
In some breeding programmes, family-tanks have been used for recording of feed consumption of sib groups. This requires a large number of small tanks, and individuals are not recorded. These increase costs and reduce the efficiency of selection in commercial operations. In NewTechAqua, an experiment is conducted that uses family-tanks as a base line method. Nofima researcher Bjarne Hatlen reports on substantial differences in the feed intake of the different families.
NewTechAqua and AquaIMPACT share a common experimental setting
Feed intake of individual fish can be estimated by including radio opaque markers in fish feed, and then by quantifying the consumed markers in an X-ray of the fishes.
AquaIMPACT has access to the siblings of the NewTechAqua family feed intake -experiment in which individuals have been also recorded for X-ray based feed intake.
Nofima researcher Gareth Difford and his colleagues can now study the potential of individual level recording of feed consumption, body composition and genomics to improve feed efficiency. ‘With genomic information we may be able to use less tanks and access more of the genetic potential at individual level’, states Difford.
In genomic selection, thousands of DNA markers are used to predict the genetic potential of broodstock fish to transmit favorable traits to offspring. A comparison will be made to traditional methods that use only family means of feed intake as a selection criteria.
EU-funding important for aquaculture in EU
‘In AquaIMPACT, we have similar work on feed efficiency of European sea bass and rainbow trout, and the joint forces help us to learn from each other’, says the AquaIMPACT coordinator Antti Kause.
Alessio Bonaldo, the NewTechAqua coordinator, acknowledges that ‘The Horizon 2020 funded projects and financial support of Nofima’s internal project are a unique opportunity to perform international collaboration between industry and RTD partners for the benefit of the aquaculture industry and consumers, and the common use of experimental resources provides even further added value’.
Nofima researchers Bjarne Hatlen & Gareth Difford
Picture: The photo shows an Atlantic salmon with visible beads that have been incorporated in the feed by manufacturing. This information is used to estimate individual feed intake and feed efficiency in the fish.