Information about cloning in a balanced way
Cloning is one of the breeding technologies that is raising a lot of discussion in Europe. Like all new technologies it must be assessed through a wide range of angles: animal welfare, food safety, precautionary principles and ethical concerns. There is great need for more clarity about these aspects and about the dangers stemming from misunderstanding. In what concerns food production, benefits of cloning are limited at present, but potentially promising in the long term. Cloning allows the reproduction of animals that already have shown good productivity, a low incidence of disease and ability to cope with the environment.
The principle of cloning
Cloning is a relatively new reproductive technology for farm animals. Potentially it can be used to produce genetic copies of individuals and for dissemination of genetic progress but it may also be used to introduce a new or endangered breed into a country without risk of disease transmission by transport of animals. Today cloning in farm animal breeding is done mainly for research purposes and not for production of milk, meat or eggs.
Animal clones can be created in two ways: by splitting an embryo, and by Somatic Cell Nuclear Transfer (SCNT).
Cloning for genetic insurance and diversity.
Cloning of animals with exceptionally high genetic value: for example, an Aberdeen Angus bull whose offspring show unusually high disease resistance is still being investigated in Texas A&M University though the original bull is long dead; offspring are being derived from his clone. The accidental loss of such animals would be highly damaging to genetic improvement, and to breeding company success. In horses, castrated stallions have been made available for breeding again by cloning them. The cost of cloning is relatively low compared with what has been invested in such animals already, and cloning would be feasible as an insurance policy.
The use of cloning from frozen somatic tissue is a much more cost-effective strategy for bio-banking of endangered breeds than the storage of sperm or egg cells. Sample collection and storage will be much easier and cheaper, the technique can be deployed quickly in emergency situations such as a disease outbreak, and cloning recovers all the genetic variation of the donor – not just half of it as when using sperm.
Cloning has been used this way to conserve the Enderby Island (New Zealand) and Bleue de Bazougé (France) cattle breeds, and the European wild sheep (mouflon).
Cloning as a tool for Agricultural breeding programmes
Cloning is a reproductive technology, not a genetic technology. Consequently it can be used to improve the dissemination of genetic improvement, in different ways for different animal species and applications.
Research and development.
Cloning provide a new research tool to explore interactions between the genotype and environment (e.g. nutrition, disease, housing) for production traits – because the animals are more similar genetically and therefore produce less "statistical noise" and other environmental effects can be tested more efficiently.
Also, it is possible to study the basic biological processes behind growth, development, disease resistance, behaviour and other animal welfare characteristics, and epigenetic effects.
Cloning is nothing extraordinary, but part of a continuum in where science and knowledge develop new ideas. Nature itself produces clones in mammals when identical twins are born.
Bio security and food safety.
Food produced from cloned animals is in legislation also called 'novel foods'. The first legislation on novel foods was introduced in May 1997. Novel foods include foods derived from animals obtained by breeding methods not used in Europe before 1997. This is the case for cloning. The novel foods regulation requires a premarketing assessment of such foods and a specific regulation authorising them. Until the present there was not any request from any interested party to trade such products. The reason for this is that cloning is not aimed to produce animals that would go to the food chain, but to preserve a breed or for elite animals mainly used for breeding.
As indicated by EFSA and other food safety assessments (1,2) there are no identified food safety risks associated with products (milk, meat) derived from clones or their offspring: In reality, the composition of food products from cattle, swine, and goat clones, or the offspring of any animal clones, is no different from that of conventional breeds.
In spite of the fact that it is recognised that cloning does not raise food safety concerns, a large number of people have doubts about the interest of use of this technology. They refer to concerns related to animal welfare, animal health and ethics.
The European Parliament reiterated its opposition to meat and milk produced from cloned animals on the 7th of July 2010, piling pressure on the European Commission to ban food produced in this way. (read the article)
Animal Welfare
The main risks of SCNT cloning involve animal welfare. At present there are adverse effects related to an increased incidence of developmental abnormalities in SCNT-cloned cattle and sheep. We envisage these problems to reduce significantly with further development of the technology through research. As long as such problems exist, SCNT cloning cannot play any significant role in the animal production sector – if only because it is so expensive, and animals with abnormalities cannot be used for breeding, so effectively they add to the inefficiency of the method. When the technology improves, the welfare and health problems must and will reduce, and cloning may become applied in certain parts of animal breeding for food as mentioned above.
As pointed out in the EFSA opinion (1) such developmental abnormalities are not appreciably different in incidence among SCNT-cloned pigs than among pigs produced by natural mating.
Conclusion
The benefits for food production are limited at present, but potentially promising on the long term, and the European animal production sector must maintain its global competitiveness and is too vulnerable to be able to afford missing out on such developments; particularly where competing organisations outside Europe have unlimited access to the technology.
The adverse effects of the technology are limited at present and will reduce with further developments. They are similar to those of other breeding techniques. They can be managed with adequate competence in the field of animal breeding, and Europe is particularly strong in this field.
Cloning is already used in several countries globally, mainly for the preservation of endangered species and for the production of elite animals used in breeding. The improvement in the use of the technique will allow its wide application for other purposes like biodiversity, production of medicinal products, and research.
References used in this text:
1. Scientific Opinion of the Scientific Committee on a request from the European Commission on Food Safety, Animal Health and Welfare and Environmental Impact of Animals derived from Cloning by Somatic Cell Nucleus Transfer (SCNT) and their Offspring and Products Obtained from those Animals. The EFSA Journal (2008) 767, 1-49.
2. FDA (Food and Drug Administration), 2008. Animal Cloning: A Risk Assessment. Center for Veterinary Medicine, U.S. Food and Drug Administration, Department of Health and Human Services, Pages 1-968, http://www.fda.gov/cvm/CloneRiskAssessment_Final.htm.
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