Researchers in New Zealand have genetically engineered a cow to produce milk with very little of an allergy-causing protein.
The technique, called RNA interference, reduces activity of certain genes without eliminating them completely.
With mothers breastfeeding less, cows’ milk is an increasing source of protein for babies, even though two to three per cent of infants are allergic to it.
The GM cow produced milk with a 96-per-cent reduction in the protein beta-lactoglobulin, a component known to cause allergic reactions. While there are dairy industry processes that can reduce the allergenic potential of normal milk, they are expensive and can result in a bitter taste.
The research “offers a good example of how these technologies can be used to provide alternative strategies to current manufacturing processes,” said Bruce Whitelaw, professor of animal biotechnology at the University of Edinburgh.
The same technique could be used to improve a cow’s defence against infection, he said.
“Time will tell how widely applicable RNA interference will be in GM livestock. But this is certainly a milestone study in this field,” he said.