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Xelect and Australis announce game-changing gain from trial

For aquaculture producers, feed is commonly the largest single expense, typically representing more than two-thirds of total production costs. Looking to find innovative ways to improve feed conversion efficiency, Vietnam-based barramundi producers Australis Aquaculture partnered with Xelect in 2018, and have been running an advanced genetics-backed breeding program.

Through studying genetics, researchers have been shown they can deliver significant improvements in key traits such as growth and disease resistance, however, the link between genetics and feed efficiency has been less well understood. Feed conversion ratio (FCR) is the standard measure used to assess food efficiency in livestock, and is the ratio between the amount of food consumed and the weight gained. Therefore, a lower FCR translates into a large reduction in cost.

As fish are communally raised in very large number, feed conversion efficiency is notoriously difficult to measure. Recent scientific discoveries suggest that other characteristics can serve as a useful proxy. For example, fasting tolerance has been shown to be highly correlated with conversion efficiency.

“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 per cent improvement in FCR over low weight maintenance individuals,” said Dr. Marie Smedley, senior breeding programme manager at Xelect. “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 programme. The trial was concluded in November, but we’ve already been able to apply the findings commercially to the breeding programme”.

Australis research and development (R&D) manager, Bartek Wieczorek, DVM further commented, “Evaluating fasting tolerance gives us an accessible means to precisely evaluate individuals and assign breeding values for feed efficiency without compromising fish welfare”.