West Africa’s ancient (humpless) N’Dama cattle (white) are genetically resistant to the disease trypanosomosis while East Africa’s Improved Boran (humped) cattle are susceptible to this tsetse-transmitted disease (photo credit ILRI/Elsworth).
Xinhuanet, the Chinese Xinhua News Agency online service, reports on an international research team that used a new combination of approaches to find two genes that may prove of vital importance to the lives and livelihoods of millions of farmers in a tsetse fly-plagued swathe of Africa.
‘The research, aimed at finding the biological keys to protection from a single-celled trypanosome parasite that causes both African sleeping sickness in people and a wasting disease in cattle, brought together a range of high-tech tools and field observations to address a critical affliction of some of the world’ s poorest people.
‘”The two genes discovered in this research could provide a way for cattle breeders to identify the animals that are best at resisting disease when infected with trypanosome parasites, which are transmitted to animals and people by the bite of infected tsetse flies,” said senior author Steve Kemp, a geneticist on joint appointment with the Nairobi-based International Livestock Research Institute (ILRI) and the University of Liverpool.
‘The researchers drew on the fact that while the humped cattle breeds characteristic of much of Africa are susceptible to disease-causing trypanosome parasites, a humpless West African breed, called the N’Dama, is not seriously affected by the disease.
‘The team’s results were published late on Tuesday in the Proceedings of the National Academy of Sciences (PNAS). . . .
‘Although best known for causing human sleeping sickness, the trypanosome parasite’s most devastating blow to human welfare comes in an animal form, with sick, unproductive cattle costing mixed crop-livestock farmers and livestock herders huge losses and opportunities.
‘The annual economic impact of “nagana,” a common name in Africa for the form of the disease that affects cattle (officially known as African animal trypanosomiasis), has been estimated at 4 to 5 billion U.S. dollars.
‘In a vast tsetse belt across Africa, stretching from Senegal on the west coast to Tanzania on the east coast, and from Chad in the north to Zimbabwe in the south, the disease each year renders millions of cattle too weak to plow land or to haul loads, and too sickly to give milk or to breed, before finally killing off most of those infected.
‘This means that in much of Africa, where tractors and commercial fertilizers are scarce and prohibitively expensive, cattle are largely unavailable for tilling and fertilizing croplands or for producing milk and meat for families.
‘The tsetse fly and the disease it transmits are thus responsible for millions of farmers having to till their croplands by hand rather than by animal-drawn plow.
‘If further research confirms the significance of these genes in disease resistance, a conventional breeding program could develop a small breeding herd of disease-resistant cattle in 10–15 years, which could then be used over the next several decades to populate Africa’s different regions with animals most suited to those regions.
‘Using genetic engineering techniques to achieve the same disease-resistant breeding herd, an approach still in its early days, could perhaps be done in four or five years, Kemp said.
‘Once again, it would be several decades before such disease- resistant animals could be made available to most smallholder farmers and herders on the continent. “So it’s time we got started, ” said Kemp.
‘This genetics of disease resistance research was led by scientists from ILRI in Africa and from the British universities of Liverpool, Manchester and Edinburgh, and involved researchers from other institutions in Britain, Ireland and South Korea. . . .’
Read the whole article at Xinhuanet (Xinhua News Agency, China): Livestock genes identified to unlock protection from animal plagues, 18 May 2011.
Watch below a short (5-minute) film, ‘Battling a Killer Cattle Disease’, produced by ILRI, that provides background and context for this research breakthrough.