A team from the China Agrcultural University is reporting success after transfering human genes into a herd of 300 dairy cows. The cows now produce milk containing proteins associated with human breast milk.
Human milk is beneficial to infants due to its high nutrient concentration. Formula milk offers an alternative to breastfeeding, but critics feel it is inferior and the research team hopes genetically modified cows could provide a solution. "Within 10 years, people will be able to pick up these products at the supermarket," claims Professor Ning Li, research leader and head of the university's State Key Laboratory for AgroBiotechnology. "We aim to commercialize some research in this area in coming three years."
The new research, published in the journal Public Library of Science One, named three human proteins present in the cows' milk. Lysozyme protects babies from bacteria, lactoferrin boosts the cells in an infant's immune system and alpha-lactalbumin was also present. All are found in human breast milk.
"Our study describes transgenic cattle whose milk offers the similar nutritional benefits as human milk," Li wrote in the journal. "The modified bovine milk is a possible substitute for human milk. It fulfilled the conception of humanising the bovine milk." The cows are otherwise identical to normal cows and were produced by introducing the genes to cloned embryos, which were then reared by surrogate mothers.
The laws surrounding genetically modified food research are tighter in Europe than China, but similar products have been sold legally in the United States for years. European consumers often avoid genetically modified foods, and therefore some supermarkets avoid stocking them.
European campaigners are concerned about food safety and animal welfare; the Chinese team performed two studies on a total of 42 transgenic calves. Ten died soon after birth and six more did not survive beyond six months. It is not fully understood why survival and development is affected by cloning, which is used in the genetic modification process, but researchers concede it does happen.
The Royal Society for the Prevention of Cruelty to Animals, a UK organisation, said it is "extremely concerned" by the development. A spokesperson for the organisation said: "Offspring of cloned animals often suffer health and welfare problems, so this would be a grave concern. Why do we need this milk — what is it giving us that we haven't already got?"
A University of Nottingham professor specialising in genetic modification, Keith Campbell, rejected food safety concerns. "Genetically modified animals and plants are not going to be harmful unless you deliberately put in a gene that is going to be poisonous," he said. "Why would anyone do that in a food?" The Chinese team says cow welfare will be improved as they will be better able to fight udder infection with human proteins.
