How are genetically engineered farm animals produced, in practical terms?
To obtain the large numbers of egg cells required, the female animal (say, a pig) is ‘superovulated’, by a series of hormone injections. Then, to produce embryo cells, the female is artificially inseminated. The fertilised embryo cells are recovered from the female, usually by surgery or slaughter. Large numbers of the replica gene from another species (say, a human) are injected, under the microscope, into the pig embryo cells – a process called ‘microinjection’. The microinjected embryo cells are then implanted into a second female – the ‘surrogate’ mother. This usually requires another surgical operation. When the genetically engineered foetuses are fully developed, they are born; sometimes delivery is achieved by surgically removing the surrogate mother’s uterus. Compassion In World Farming (CIWF) is totally opposed to these surgical and invasive procedures, which are not performed for the animal’s benefit. Is this a precise, well-controlled process? No. In particular, microinjecti
