Genetic diversity of livestock is being lost. The number of breeds has markedly declined over the past half century. Up to 30% of global mammalian and avian livestock breeds (i.e., 1,200 to 1,500 breeds) are currently at risk of being lost and cannot be replaced.
Breeds become rare, either because their characteristics do not suit contemporary demand or because their qualities have not been recognised. When a breed population falls to about 1,000 animals, it is considered rare and endangered.
Examples given in Thrupp, L.A. (1998) serve to emphasise the extent of the problem.
Local breeds are better adapted to their environment
Causes of genetic erosion in domestic animals
|Inappropriate Aid||Lack of appreciation of the value
of indigenous breeds and their importance in niche adaptation.
Incentives to introduce exotic and more uniform breeds from industrialised countries
|Product-focused selection||Undue emphasis placed on a specific product or trait, leading to the rapid dissemination of one breed of animal at the expense of others|
|Changes in land use||Conversion of rangelands and mixed farming systems for agriculture, game parks, and industrial use|
|Changes in knowledge||The idea that "modern/imported is best" has led to the loss of knowledge about traditional livestock husbandry practices and to the erosion of domestic animal diversity|
|Change in Technology||Replacement of animal draught and transport by machinery, leading to permanent change of farming system, artificial insemination and embryo transfer leading to rapid replacement of indigenous breeds|
|Change in Economy||Decline in economic viability of traditional livestock production systems|
|Intensification||Livestock populations that rely
on veterinary services and on improved feeding conditions. Heavy investment
in preventative and curative veterinary measures, and in feeding, housing
Multipurpose local species and breeds replaced by those with higher milk, meat, egg production (including cross-breeds and pure-bred exotics)
|Cross-breeding||Predominance of sires from a few selected breeds in widespread cross-breeding programmes can lead to loss of features expressed by specialised breeds|
|Storage||Failure of cryopreservation equipment (used to freeze semen, ova and embryos) or lack of refrigerant, inadequate maintenance of frozen semen from breeds that are not in demand|
|Conflict||Wars and other forms of socio-political instability can lead to livestock owners moving their stock out of their usual area, thus increasing the possibility of mixing with other breeds thereby potentially losing a location-specific breed|
|Disaster||Natural disasters such as floods, drought or famine can result in whole breeds dying out|
These trends are supported by:
Ironically, the loss of indigenous breeds that are able to exploit vegetation in the more extreme environments also seriously affects the capacity of human society to live in large areas of the world in a sustainable manner.
Declining livestock diversity has serious consequences for current livestock production and future capacity to meet unforeseen challenges and opportunities. Livestock diversity is being lost partly because of commercial production.
For instance, commercial production of egg chickens, meat chickens, and turkeys is dominated by fewer than 10 multinational breeding companies. Breed-level diversity within egg and meat-producing types is low because common breed origins and intense selection for similar production goals have promoted genetic uniformity. Similarly, China possesses at least 50, and perhaps over 100, unique pig breeds, but many of these are becoming endangered as they are replaced with western breeds.
Examples given in Thrupp (1998) also serve to emphasise the current status of livestock diversity. "FAO estimates that somewhere in the world at least one breed of traditional livestock dies out every week. Many traditional breeds have disappeared as farmers focus on new breeds of cattle, pigs, sheep, and chickens. Of the 3,831 breeds of cattle, water buffalo, goats, pigs, sheep, horses, and donkeys believed to have existed in this century, 16 percent have become extinct, and a further 15 percent are rare. Some 474 of extant livestock breeds can be regarded as rare. A further 617 have become extinct since 1892. Over 80 breeds of cattle are found in Africa, and some are being replaced by exotic breeds."
Traditional pastoralists have often tended to foster biodiversity, in both plants and animals. Many pastoral societies have developed elaborate systems that result in the preservation of genetic resources. Pastoralists have deliberately developed livestock to meet different needs and conditions. For example, a least 12 breeds of camel are known from southern Sudan alone. However, wealthier sectors of society are now accumulating large livestock holdings through purchase of animals from different areas and tribal groups - with the resulting cross-breeding making camels of one generic type.
It is clear that livestock breeds are not biological taxa but rather represent the outcome of social processes. They are therefore unlikely to survive outside the social contexts and production systems that formed them. However, these losses weaken the potential of breeding programs that could improve hardiness of livestock.
Commercial breeds of livestock possess greater genetic variability than most crop varieties do. This diversity allows intensification of selection within breeds to be a fruitful approach for improving livestock productivity. However, if continued emphasis on breed replacement and increasing selection intensity (e.g. for greater productivity) take place at the expense of maintenance of genetic diversity, including the advantages of disease resistance and environmental adaptation, there may be significant long-term costs. As an example, Holstein cattle have become the pre-eminent dairy breed world-wide and have enjoyed sustained improvements in milk production potential, but only at the cost of declining genetic diversity within the breed.
Despite significant advances in the preservation of genetic diversity of crop varieties, for example through ex-situ preservation of germplasm and seed banks, little attention has been paid to conserving the genetic diversity of livestock species. The current dependence on in situ conservation by hobbyists is inadequate. Moreover, this form of breed preservation is currently largely limited to Europe and America. The significant livestock diversity in Africa, Asia and South America is largely unprotected.
State is therefore characterised by:
It is important that the genetic diversity of rare and endangered livestock breeds and their wild relatives and ancestral lines be preserved as insurance for future needs.
Formal government-sponsored international programs for in-situ and ex-situ preservation of livestock genetic diversity need to be established. In addition, the native habitats of the wild relatives of livestock species must be preserved.
Investments in preserving this natural capital could yield net payoffs in both agricultural productivity and profitability. Such investments should be considered in any economic cost-benefit analyses of alternative production regimes.
A move towards sustainable agriculture requires changes in production methods, concepts, and policies, as well as the participation of local people. Scientific advancements in genetics and "improved" varieties can have important roles. However, these need to be reoriented towards conserving and using diversity in farming systems - rather than replacing diversity with uniformity. The following principles are important:
References and Further Reading:
Cattle Diversity Database. http://www.ri.bbsrc.ac.uk/cdiv_www/accessdb.htm
Collins, W.W. & Qualset, C.O. (1999). Biodiversity in agroecosystems. CRC Press. (CRC Press LLC, 2000 Corporate Blvd., N.W. Boca Raton, Florida 33431, USA).
Convention on Biological Diversity. Click to view document
Department of Animal Science - Oklahoma State University. Breeds of Livestock. http://www.ansi.okstate.edu/breeds/
Intermediate Technology (1996). Dynamic Diversity: Livestock keepers safeguarding domestic animal diversity through their animal husbandry. Intermediate Technology Development Group, Myson house, Railway Terrace, Rugby, CV21 3HT, UK. (Email: firstname.lastname@example.org)
Mason, I.L. 1996. A World Dictionary of Livestock Breeds, Types and Varieties. Fourth Edition. C.A.B International. 273 pp.
McNeely, J.A., Gadgil, M., Leveque, C., Padoch, C. & Redford, K. (1995). Human Influences on Biodiversity. Pp 711-821 in. Heywood, V.H. & Watson, R.T. Global Biodiversity Assessment. UNEP. Cambridge University Press. ISBN 0-521-56481-6.
Rare Breeds Canada. c/o Trent University Environmental & Resource Studies Program Peterborough, ON, Canada, K9J 7B8. Email: RAREBREEDSCANADA@TRENTU.CA. Web Site: http://www.trentu.ca/rarebreedscanada/
Rome Declaration on World Food Security and World Food Summit Plan of Action. World Food Summit, Rome 13-17 November 1996.
The Analysis of Genetic Diversity in Cattle to Preserve Future Breeding Options. http://www.ri.bbsrc.ac.uk/cdiv_www/homepage.htm
Thrupp, L.A. (1998). Linking Biodiversity and Agriculture: Challenges
and Opportunities for Sustainable Food Security. World Resources Institute.
FAO Global Strategy for the Management of Farm Animal Genetic Resources
FAO. The FAO Global Strategy for the Management of Farm Animal Genetic Resources. Domestic Animal Database. http://dad.fao.org(opens in a new browser window) and also the following related documents.
|Brochure: The Global Strategy for the Management of Farm Animal Genetic Resources.|
|Some detail on the Global Strategy for the Management of Farm Animal Genetic Resources|
|Primary Guidelines for Development of National Farm Animal Genetic Resources Management Plans|
|Secondary Guidelines for Development of National Farm Animal Genetic Resources Management Plans. Animal Recording for Medium Input Production Environment|
|Secondary Guidelines for Development of National Farm Animal Genetic Resources Management Plans. Executive Brief|
|Secondary Guidelines for Development of National Farm Animal Genetic Resources Management Plans. Management of Small Populations at Risk|
|World Watch List for Domestic Animal Diversity, 2nd Edition|
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