Tuesday, October 02 09:52:03
Scientists at the University of Waikato in Hamilton, New Zealand, have created a genetically modified (GM) cow that produces milk with low levels of a protein known to cause allergic reactions in a significant proportion of children. The researchers believe it could one day lead to the sale of "hypoallergenic" milk from herds of GM cows. The calf had been cloned and genetically engineered with an extra piece of genetic material that switched off its natural gene for producing a milk protein called beta-lactoglobulin, which is not present in human milk and causes allergies in some young children.
Tests on the cow's milk showed that it contained less than 2 per cent of normal levels of beta-lactoglobulin and was far richer than usual in other kinds of milk proteins, such as the caseins used in cheese-making. The researchers also believe the GM cow's milk will also contain higher concentrations of calcium than ordinary milk. The cow, however, was born without a tail which is a rare congenital abnormality. The scientists believe this was a result of the cloning process, similar to that used to create Dolly the cloned sheep, rather than the GM technique used to eliminate the milk protein.
The dairy industry produces hypoallergenic milk formulas by removing certain bovine proteins with the help of digestive enzymes but the industrial-scale processing is expensive, causes the milk to taste bitter and does not always remove the offending allergens, the scientists said.