*EPF107 01/24/00
Biotechnology Is Changing the Face of Animal Agriculture
(Expert cites growing demand for meat and milk products) (1090)
By Jim Fuller
Washington File Science Correspondent

The Hague -- A leading researcher in animal science says that biotechnology is offering new opportunities to increase the productivity of livestock needed to meet a growing demand for meat and milk products in developing countries.

Tony Irvin, director of biosciences at the International Livestock Research Institute (ILRI) in Kenya, said January 21 that the consumption of livestock products in developing countries is expected to nearly double over the next decade to meet changing dietary demands driven by increasing urbanization and rises in per capita income.

Irvin, speaking to political and research experts attending a two-day biotechnology conference in The Hague, said the challenges represented by these changing demands "are considered by some to be as great as those that led to the Green Revolution of the 1970s."

The Green Revolution, which brought food security to millions of people in developing countries, was brought about through the application of new technologies in plant genetics. Irvin said that grain production, in broad terms, is sufficient to meet global needs for now, but that demand for livestock products will increase disproportionately as compared to crops over the next decades.

Irvin pointed out that livestock are absolutely critical to the survival of small farm systems in developing countries, producing such things as wool and leather, providing draught animals for tillage, and producing manure for fertilizer.

"In some ways, the milk and meat provided by livestock is actually a bonus - a byproduct," he said in an interview. "The primary need in some of these situations is the manure used for fertilizer or the draught animal for plowing."

Irvin went on to say that while health and genetic constraints are major impediments to improving livestock in developing countries, providing a sufficient quantity and quality of feed is probably the biggest obstacle to increasing herds. In countries such as India and Bangladesh, livestock subsist largely on crop residues and wastes -- straws that are often deficient in key nutrients.

"Animals are being required to be productive on diets that would not even allow survival of Western breeds let alone additional output in terms of production," Irvin said. "On the Indian sub-continent, for example, because nearly all the agriculture is taken up with crop production, there's very little grazing as we think of it in the Western context. There's a little bit of roadside grazing. But a lot of that is cut-and-carry."

Irvin said that biotechnology can enhance the quality of plant residues on which most livestock feed. For example, genetic breeding techniques can be used to introduce genes related to a particularly desirable characteristic, such as the so-called "stay-green" trait, which can increase the nutritional value of residues from crops such as maize, sorghum and millet.

"With this trait, after the crop has produced its grain it stays green, giving it much greater nutritional value than it has when it becomes withered and dried up, as happens under normal conditions," Irvin said.

He said another approach is to genetically alter crops to increase the ratio of leaf-to-stem. "This is because the leaf has more nutritive value than the stem," he said. "One can also accomplish this through conventional breeding and selection technologies."

Irvin said researchers are also trying to identify the microorganisms in the stomachs of animals that have adapted to feeding on poor quality crop residues and wastes. These microorganisms, which are responsible for metabolizing feed in ruminant animals, such as horses and cows, and breaking down anti-nutritive substances, can be used to improve the nutritive value of poor quality feeds such as straws, or detoxify potentially toxic plants that are high in protein, such as certain legumes.

"This research also includes looking at wild animals - the wild antelopes of Africa, for example - that subsist and are productive in environments where domestic livestock find it very difficult to survive," he said.

Irvin said biotechnology can also be used to characterize and identify markers linked to unique genes that have allowed indigenous livestock in developing countries to become highly resistant to endemic diseases, tolerant of heat and drought, and able to survive on poor quality feed.

"Although livestock in these environments often appear, through Western eyes, to be malnourished and stunted, and they may lack the genes for high milk or meat production, they are nonetheless exquisitely adapted, through natural selection, to survive and be productive," he said.

Irvin said, for example, that genetic markers associated with tolerance to bovine trypanosomosis, a tropical disease, have been identified in Ndama cattle from West Africa, and markers linked to resistance to haemonchosis, a disease caused by a gastro-intestinal parasite, have been identified in Red Maasai sheep in East Africa. Marker-assisted selection (MAS) programs are now being applied to introduce these genetic traits into breeds with higher production potential.

"The application of MAS and other advanced genetic techniques, in order to combine the resistance genes of livestock from developing countries with the production genes of developed country livestock, could one day provide the optimal animals for both tropical and temperate environments," Irvin said.

Irvin said genetic techniques could also be applied to identify and isolate highly specific antigens for development of improved vaccines against specific diseases.

"Although the major pandemic diseases of livestock, such as rinderpest and foot-and-mouth disease, can be effectively controlled by vaccines in developed countries, their control is not always effective in developing countries where distribution channels, cold chains and vaccine affordability pose serious problems," he said. "Furthermore, there are a number of tropical diseases for which effective vaccines are still lacking."

He said genetic techniques could provide the means of making vaccines that are strain-specific against target organisms, heat-stable for use in tropical climates, and more readily affordable by poor people.

"In the longer term, vaccines will be developed that allow concurrent vaccination against several diseases," he said.

Finally, Irvin said it is vital that the unique genetic pool of indigenous livestock breeds, as well as wildlife, that exist in many developing countries be conserved so that valuable genetic material is not lost through cross breeding or neglect. A major international program, sponsored by organizations like the Food and Agriculture Organization of the United Nations and the ILRI, is seeking to identify and conserve key populations and breeds and preserve this rich biodiversity for future generations.

(The Washington File is a product of the Office of International Information Programs, U.S. Department of State)
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