“A genetically modified cow whose milk lacks a substance that causes allergic reactions in people has been created by scientists in New Zealand.
In their first year of life, two or three in every hundred infants are allergic to a whey protein in milk called BLG. The researchers engineered the cow, called Daisy, to produce milk that doesn’t contain the protein.
While the genetic alteration slashed levels of BLG protein in the cow’s milk to undetectable levels, it more than doubled the concentrations of other milk proteins called caseins.
The cow was created with the same cloning procedure that led to Dolly the sheep in 1996 and was delivered by caesarean at the government-owned AgResearch lab in Hamilton.
Most of the differences between cow and human milk do not cause problems for people who consume it, but BLG or beta-lactoglobulin protein, which is found in milk from cows and other ruminants, is a major cause of allergic reactions.
Stefan Wagner, a scientist on the team, said they now plan to investigate whether or not the BLG-free milk causes allergic reactions.
“First of all, we will have to determine whether the lack of detectable levels of BLG will impact on milk yield,” said Wagner.
The work also drew on a technique that gives scientists precise control over which genes are active in an animal, and gives fresh momentum to plans to engineer cows, pigs, sheep and chickens that are more resilient to diseases….”