through the smoke-screen
Genetic engineering is happening but how many of us actually understand what it involves. This article from Compassion in World Farming (CIWF) clearly explains the process and what the consequences are, especially for animals.
|By Dr. Tim O'Brien|
What is genetic engineering?
Genetic engineering is the artificial manipulation of the DNA, or genes, of living things.
Is it harmful to farm animals?
It is clear from scientific reports that farm animal genetic engineering has adversely affected farm animal welfare.
Is farm animal genetic engineering the same as selective breeding?
No. Selective breeding, for farm animals, generally means crossing one species with another individual of the same species resulting, for example, in chickens which grow so quickly that their legs can't carry the weight of their bodies.
Genetic engineering is a completely different thing. It usually involves taking one or a few genes from one species (sheep, rats, or even humans) and putting these genes (or replicas of them) into an entirely different species (for example, a cow or a pig).
Why do some people want to do this?
ï To produce animals which grow faster, and which therefore reach slaughter weight more quickly.
ï To produce animals which are more productive - animals, for example, which will produce more wool or more milk.
ï To produce animals resistant to diseases. But what diseases? Some scientists are trying to produce animals which are resistant to the diseases of overcrowded and unhygienic factory farms.
ï To produce animals which make medicine in their milk or eggs - but alternatives are usually available which do not involve animal suffering.
ï To produce animals which are spare-part factories for human transplant operations ('xenotransplants').
Some business investors believe that there may be an opportunity for big profits.
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, microinjection of the new gene into the embryo is a problem area.
If the embryo is more than one cell big, the new gene may be incorporated only into some of the cells - a 'chimera' results, where part of the animal is genetically engineered and part is not (remember the 'geep' - half sheep, half goat?). In this situation, the animal's development can be seriously impaired.
The new gene may add itself to the embryo's DNA the wrong way round, or several times instead of once, or in the wrong place, or a combination of all of these things may occur. The new gene may even mutate on insertion. You can imagine the disruption to the animal's development which can ensue.
The correct development of farm animals is governed by the interplay of 50-100,000 genes; we know the function of 1-2% at the most. Adding new genes from different species is like playing with a chemistry set with no labels, except that in the case of farm animal genetic engineering, the experimental material is living things which can suffer and feel pain.
When did farm animal genetic engineering start?
The first genetically engineered farm animals were produced in 1985. Some were pigs, with added cow or human growth hormone genes. They were produced in the United States Department of Agriculture research station, at Beltsville, in Maryland, and became known as the 'Beltsville Pigs'.
The pigs suffered from liver and kidney damage, ulcers, damaged vision, they were lame .... of course, the scientists involved implied that this was an early experimental failure, which might be expected at first, but that things would improve over time.
More than ten years later, not one of the promised benefits of genetically engineered farm animals has been delivered, but every month brings new scientific papers describing animal casualties.
For example, a calf was given genetic material normally found in a chicken. At eight weeks old, the calf seemed alright, at 15 weeks old, the calf was destroyed - its muscles had turned like jelly.
And last year, there were reports of genetically engineered salmon with added 'antifreeze' genes - the salmon were coloured green, with gill and cranial deformities which led to 'reduced viability'.
What is ClWF's position?
CIWF is totally opposed to the genetic engineering of farm animals. This hit and miss technology involves unethical reproductive procedures, and has a huge potential to cause suffering. It must end NOW.
More information about modern breeding technologies and farm animal genetic engineering is available in the following CIWF Trust reports: Modern Breeding Technologies and the Welfare of Farm Animals by Joyce De Silva and Peter Stevenson, and Gene Transfer and the Welfare of Farm Animals by Dr Tim O'Brien; price £2.50 each, from CIWF Trust, Charles House, 5A Charles Street Petersfield, Hants UK, GU32 3EH. Please make cheques payable to CIWF Trust.
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