Pharming has been milking rabbits experimentally for years, and recently developed a drug called Rhucin from the rabbit milk-derived C1 inhibitor protein. If the drug is approved in Europe, Pharming would start milking a herd of about a thousand rabbits.
The rabbits are milked using mini pumping machines that attach to the female rabbits' teats. The method "can roughly be compared to cow milking, but of course on a smaller scale," de Vries said. And like dairy cows, the rabbits stay relaxed and appear to suffer no discomfort during milking.
Thanks to human genes spliced into their genome, the mice are the first genetically modified animals to produce lactoferrin. This human breast milk protein protects babies from viruses and bacteria while the infants' immune systems are still developing.
To milk mice, the research team had to anaesthetize the rodents and use specially adapted pumps fitted to their tiny teats.