Loch Duart has switched to an all-natural fish feed ingredient to give its farmed salmon their pink hue.

The new feed, named Panaferd, is produced by drying a natural organism containing the pigments eaten by wild salmon.

"To have all the colour in our salmon derived from naturally occurring organisms is the culmination of years of hard work," said managing director Nick Joy. "As a farmer, I am proud that we rear well-nourished salmon that look and taste great."

Loch Duart had failed to source the ingredient in the past due to supply issues.

Meanwhile, export volumes of Scottish salmon soared 24% in 2009 to 65,480 tonnes, new figures show.

"With demand for Scottish salmon extremely high overseas, export markets offer further opportunity for expansion," said Scott Landsburgh, chief executive of the Scottish Salmon Producers' Organisation.