Pigs produced to be resistant to one of the world’s most costly livestock diseases have been approved for sale to US consumers.

The US Food and Drug Administration has approved the use of a gene-editing technology that makes pigs resistant to Porcine Reproductive and Respiratory Syndrome (PRRS) for the US food supply chain.

This approval for animal genetics company Genus, following years of development, helps meet the challenge of a disease that is endemic to most pig-producing regions.

The infection, which causes fever, respiratory distress, and premature births, costs the industry approximately $2.5 billion (£1.75bn) each year in lost revenue in the US and Europe alone.

Technology development

Researchers at the University of Edinburgh’s Roslin Institute focused their efforts on the CD163 gene in pigs. This gene produces a receptor on the surface of cells, which the PRRS virus uses to cause infection.

Experts removed a small section of this gene, focusing on the part of the receptor that the virus attaches to, leaving the rest of the molecule intact.

The resulting pigs do not become infected with the virus, and the animals show no signs that the change in their DNA has had any other impact on their health or wellbeing.

Professor Bruce Whitelaw, of the Roslin Institute, said: “We are delighted to see the PRRS-resistant pig gene-edit approved for use - this is a milestone in the use of gene editing in livestock, and a landmark moment for the livestock industry towards managing a global disease that causes devastating losses.”

Jorgen Kokke, CEO of Genus, said that FDA approval represents a major step towards US commercialisation.

"We will now continue to pursue regulatory approvals in other international jurisdictions with a focus on key US export markets," he said.