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. [...] ”We first of all consider our genetically modified cow a great tool to study allergenicity and do not envision any practical application any time soon,” Wagner added.