To meet the demands of the health-conscious consumer, how about developing cows that produce skim milk? Well, scientists have identified a cow that does this, and they hope to establish herds of the animals to meet the increased health demands from the public. The cows, which carry a particular genetic mutation, were bred from a single female, named Marge, who was discovered by researchers when they screened milk from millions of cattle in New Zealand.
“Marge looks like an ordinary Friesian cow but has three key differences. She produces a normal level of protein in her milk but substantially less fat, and the fat she does produce has much more unsaturated fat. She also produces milk with very high levels of omega3 oils,” said Russell Snell, the chief scientist at the biotech firm, ViaLactia.
Omega3 oils are sometimes thought to improve brain power, and the saturated fats that are normally found in cows’ milk are linked to increased risk of heart disease. Marge and her daughters produce milk with less than 1% fat. Additionally, because these cows’ milk contains so many unsaturated fats, butter made from these cows’ milk is spreadable straight from the fridge, like margarine.
Marge was discovered in 2001 and ViaLactia’s researchers bought her for £120 and moved her to a secret location. Even though they now owned Marge, the important issue was whether Marge’s calves would inherit her unique traits.
“You have to generate daughters and then they have to carry a calf and deliver milk,” said Snell. “The eureka moment was when we found her daughters produced milk like their mother.”
ViaLactia hopes Marge’s male offspring carry the same genes as her daughters. “To have a bull from Marge’s offspring who passes on her traits would be the holy grail. It would allow us to reproduce hundreds of thousands of cows like Marge,” said Snell.
Scientists are still trying to identify the genes that give Marge her special traits. Helen Wallace, of GeneWatch, the genetics watchdog, said it was important to ensure the mutations that produced the milk were not harmful in any way. “If so then using such animals would be far better than creating genetically modified cows.”