The possibility of commercially producing genetically modified drinking milk in Australia has come a step closer with the birth of Holly, Molly, Jolly and Lolly, Holstein calves given an extra gene so that their milk contains extra protein.

The calves were cloned from a top-quality cow and born to three different mothers implanted with the embryos. Advocates of the technology claim it allows milk to contain a higher proportion of its health-giving properties.

While the sisters are the first genetically modified cows born in Australia, other countries are further down the path. In the US, for instance, researchers are looking at the possibility of modifying cows so that their milk has specific medicinal properties. Clinical trials are underway on milk altered to offer treatment for haemophiliacs and cystic fibrosis sufferers – at a fraction of the cost of conventional treatment.

Holly, Molly, Lolly and Jolly were the fruit of collaborative efforts by the Monash Institute of Reproduction and Development, the Victorian Institute of Animal Science and artificial insemination firm Genetics Australia.

The technique used involved extracting a bovine protein gene from a cow’s cell, inserting it into a cloned embryo in the laboratory, then implanting the embryo into a surrogate mother cow.

The commercial production of GM drinking milk in Australia is still seven to ten years away, although production of modified milk containing genetically-produced human medicines and vaccines could be as close as five years away, reported Reuters.