Researchers in New Zealand have engineered cloned cows to produce milk with higher levels of casein to facilitate the cheese-making process.

The Hamilton-based researchers, led by Goetz Laible, engineered cells to overproduce casein proteins, then fused the cells with cow eggs. The resulting embryos were subsequently implanted in recipient cows, and 11 GM cows were born. Of these, nine produce the enhanced milk.

The enhanced milk boasts improved processing properties and heat stability, which could translate into substantial economic gains, the researchers reported. One protein, kappa-casein, improves heat stability during production, while the other, beta-casein, reduces the clotting time of rennet, which curdles the milk, according to an article published in Nature Biotechnology.

The scientists say the technique could be adapted to tailor milk for human consumption as well as for use in processing.