Scientists have altered the genes of a dairy cow to produce milk that's rich in a protein used in numerous food products and lacking in a component that causes allergies in humans.
Using a process called RNA-interference that turns certain genes on or off, scientists from New Zealand produced a cow whose milk had increased casein, a protein used to make cheese and other foods, and almost no beta-lactoglobulin, a component in milk whey protein that causes allergies. The female calf was also born without a tail, according to the report today in the journal Proceedings of the National Academy of Sciences.
The study can be seen as a proof-of-concept that tinkering with nutritional content genetically is possible, said William Hallman, director of the food policy institute at Rutgers University. More testing will be needed to determine the milk's full dietary content, and scientists must consider the effects of breeding gene-altered animals, he said. The field has been controversial because of safety and environmental concerns.