Cloned calves a first for Australia

In a first for the Australian dairy industry, four genetically modified calves have been born with an additional protein gene for milk protein production.

The cloned calves are the result of a collaboration between the Monash Institute of Reproduction and Development, Genetics Australia and the Victorian Institute of Animal Science. The project was largely funded by the Dairy Research and Development Corporation.

According to Dr Ian Lewis, senior scientist at Genetics Australia, the extra protein gene may increase the milk protein content by 25 per cent or more. Cows normally have four copies of the protein gene.

"This is an important step in our long-term quest to produce more nutritious dairy products," Lewis said. "Our aim is to develop new and improved dairy products that will add value for the consumer, for dairy farmers and for the Australian economy.

"There are lots of other nutritious and health-giving products in milk, including factors that potentially can lower blood pressure, reduce heart disease and protect against cancer."

The extra gene, for the milk protein casein, was inserted into cells from an elite dairy cow. The modified cells were fused with enucleated donor egg cells and the resulting embryos implanted into surrogate cows.

The four calves are genetically identical to each other, but two were born from separate surrogates and two were born as twins. Several more cows are pregnant with additional clones to be born later this year.

"To establish that we can do this efficiently and reliably requires four or maybe more," said Lewis. He explained that lactation in the cloned cows will be measured and compared to milk production in other elite cows.

"Lab studies suggest that it is not unreasonable to expect an increase of 10 per cent or more," said Prof Alan Trounson, director of the Monash Institute of Reproduction and Development. The scientists said they were hoping for 25 per cent or more over normal production levels.

Lewis said that the calves represented a proof of principle for genetic modification.

"The technologies we are developing have quite long lead times," said Lewis. "It may be seven to 10 years before these products are available."

The technology is also potentially useful for the manufacture of pharmaceuticals such as vaccines. Genes for the products would be expressed in the milk and the resulting product easily purified. Trounson explained that for a large volume activity, this would be a good solution.

"It could be produced in a paddock, separated in a lab and packaged and sent off around the world," he said.

Lewis and Trounson stressed the importance of gene technology and advanced breeding techniques like cloning for the dairy industry,

"We have spent 10 years developing this technology," Trounson said. "Conventional genetics is being replaced by new genetics worldwide."

"Australian dairy farmers are among the most efficient in the world," added Lewis, explaining that investments in gene technology would allow the Australian dairy industry to remain competitive with the rest of the world.