33% fewer lice

The latest breeding techniques, which select fish specifically for their resistance to sea lice, could cause parasite numbers to drop by a third. 

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So claimed Aquagen’s CEO, Nina Santi, at a seminar the company held in Bergen yesterday. “One in every third louse may disappear with the use of fish which are selected specifically with these abilities,” she said.

Her claim preceded the company’s 12th generation of salmon becoming available for sale and she was at pains to emphasise the improvements that selective breeding has had on a number of traits, not least fish growth.

From the early 70s, when they gathered wild fish to start the breeding program for salmon, there has been tremendous development using family based breeding. Fish from the 1st generation took 22 months to reach four kilograms, by the mid-90s the sixth generation had reduced this time to 16 months.

“Now we're down to about nine months to produce one 4 kg fish,” Santi explained.

She added that fish from the 12th generation which will be available this autumn, were the products of new selection technology.

“Using so-called genomic selection, we can pick out the best individuals, based on 55,000 different genetic markers,” she observed.

The breeding programme also aims to select individuals that are resistant to lice, as well as weeding out those with a negative QTL, the so-called 'lice collectors'.

Santi said that such selection is expensive but, given the lice costs that the industry faces, the method will pay off in the long run.

In addition, the company is looking for rapid growth, in order to get the fish faster through the production cycle, as well as increase their tolerance to handling, so that the fish will be able to withstand delousing.

Increased resistance to other diseases is also a criteria that modern breeding tools can target.

The result, which is backed by an Aquagen trial, is a significant reduction in lice on fish.

“We have measured a 30 to 40 per cent reduction in lice on fish. That means one of three lice are gone,” she says.

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