As feed costs rise sharply, aquaculture producers are taking steps to enhance competitiveness by finding innovative ways to improve feed conversion efficiency, it reported.
Xelect has been running an advanced genetics-backed breeding program with Vietnam based barramundi producer, Australis Aquaculture, since 2018.
“We support farmers all round the world with their genetics work. The core traits that we optimize for Australis are growth and disease resistance,” Chris Wallard, spokesperson for Xelect, told us.
The recent trial linked to feed efficiency it carried out with Australis was based on the idea of fasting tolerance, the ability for fish to maintain weight when feed is withheld for short periods. “That was a standalone piece of work but will now be incorporated into the barramundi producer’s main program,” said Wallard.
Whilst genetics has a clear track record of delivering significant improvements in key traits such as growth and disease resistance, the link between genetics and feed efficiency has been less well understood, noted the genetics company.
The findings
Feed Conversion Ratio (FCR) is the standard measure used to assess food efficiency in livestock. “However, feed conversion efficiency is notoriously difficult to measure in commercial aquaculture settings, as fish are communally raised in very large numbers.”
Recent scientific discoveries, said Xelect, suggest that other characteristics can serve as a useful proxy. For example, fasting tolerance has been shown to be highly correlated with conversion efficiency, it explained.
Dr Marie Smedley, senior breeding program manager at Xelect, commented: “Essentially, an individual that spends less energy maintaining weight has a lower maintenance energy requirement which translates to improved feed efficiency. Our latest trial with Australis suggests that significant gains are possible – with high weight maintenance groups showing a 12% improvement in FCR over low weight maintenance individuals. Because this trait is also ‘heritable’, a significant part is down to genetics. Therefore, fasting evaluations can be performed routinely to select the most feed efficient broodstock in Australis’ breeding program. The trial was concluded in November, but we’ve already been able to apply the findings commercially to the breeding program.”
Australis R&D manager, Bartek Wieczorek, said: “Evaluating fasting tolerance gives us an accessible means to precisely evaluate individuals and assign breeding values for feed efficiency without compromising fish welfare.”
