The spatial ecology of pigs: Where free-range doesn’t come free

Posted on April 9, 2013 by Susan MacMillan

A report on the economic as well as health risks of keeping free-range pigs in western Kenya has been published by scientists in the animal health laboratories at ILRI’s Nairobi, Kenya, campus; here, two of the authors, lead author Lian Thomas (left) and principal investigator Eric Fèvre (right), inspect a household pig in their project site, in Busia, in western Kenya (photo credit: ILRI/Charlie Pye-Smith).

Like your livestock products to come from free-range systems? Consider that a healthy alternative to the factory farming of livestock? Consider the lowly pig, and what serious pathogens it can pick up, and transmit to other animals and people, in the course of its daily outdoor scavenging for food. Consider also the scavenging pig’s coprophagic habits (consumption of faeces) and you may change your mind.

A recent study has brought those habits to light. The study was conducted in an area surrounding Busia town, in western Kenya (Busia lies near Kenya’s western border with Uganda; Lake Victoria lies to the south). The study was conducted by scientists at the International Livestock Research Institute (ILRI) and the University of Edinburgh to better understand the transmission of several pathogenic organisms. This is the first study to investigate the ecology of domestic pigs kept under a free-range system, utilizing GPS technology.

Most people in Busia farm for a living, raising livestock and growing maize and other staple food crops on small plots of land (the average farm size here is 0.5 ha). More than 66,000 pigs are estimated to be kept within a 45-km radius of Busia town.

ILRI’s Lian Thomas with a household pig in western Kenya (photo credit: ILRI/Charlie Pye-Smith).

A GPS collar was put on 10 pigs, each nearly 7 months old, that were recruited for this study. A handheld GPS unit was used to obtain the coordinates of the homesteads to which the selected pigs belonged; the perimeters of the homesteads and their main features, including human dwellings, cooking points, rubbish disposal areas and latrines, were all mapped. The pig collars recorded the coordinates of the pigs every 3 minutes during the course of one week.

All the 10 pigs were kept under free-range conditions, but also regularly fed supplementary crop and (mostly raw) household waste. All the pigs recruited were found to be infected with at least one parasite, with most in addition also having gastrointestinal parasites, and all carried ticks and head lice.

The pigs, which scavenge both day and night, were found to spend almost half their time outside the homestead, travelling an average of more than 4 km in a 12-hour period (both day and night), with a mean home range of 10,343 square meters. One implication of this is that a community approach to better controlling infectious diseases in pigs will be better suited to this farming area than an approach that targets individual household families.

Three of the ten pigs were found to be infected with Taenia solium, a pig tapeworm whose larva when ingested by humans in undercooked pork causes the human disease known as cysticercosis, which can cause seizures, epilepsy and other disorders, and can be fatal if not treated. T solium infection in pigs is acquired by their ingestion of infective eggs in human faecal material, which is commonly found in the pigs environments in rural parts of Africa as well as Mexico, South America and other developing regions.

This study found no correlation between the time a pig spent interacting with a latrine at its homestead and the T solium status of the pig. The paper’s authors conclude that ‘the presence or absence of a latrine in an individual homestead is of less relevance to parasite transmission than overall provision of sanitation for the wider community in which the pig roams’. With a quarter of the homesteads in the study area having no access to a latrine, forcing people to engage in open defecation, and with less than a third of the latrines properly enclosed, there are plenty of opportunties for scavenging pigs to find human faeces.

A typical household scavenging pig and pit latrine in the project site in Busia, Kenya (photo credit: ILRI/Charlie Pye-Smith).

Improved husbandry practices, including the use of effective anthelmintics at correct dosages, would enhance pig health and production in this study area.

One of the interesting findings of the study is that all this pig roaming is likely to be helping to reduce the weight of the pigs at slaughter. Mean live weights at the abattoir in the Busia area are 30 kg, giving a dressed weight of only 22.5 kg and earning the farmer only KShs.2000–2500 (USD24–29) per animal.

Encouraging the confinement of pigs is likely to improve feed conversion and weight gain, by both reducing un-necessary energy expenditure as well as limiting parasite burden through environmental exposure.

‘Confinement of pigs would also reduce the risk of contact with other domestic or wild pigs: pig to pig contact is a driver of African swine fever (ASF) virus transmission. ASF regularly causes outbreaks in this region . . . . Confining pigs within correctly constructed pig stys would also reduce the chances of contact between pigs and tsetse flies.’ That matters because this western part of Kenya is a trypanosomiasis-endemic area and pigs are known to be important hosts and reservoirs of protozoan parasites that cause both human sleeping sickness, which eventually is fatal for all those who don’t get treatment, and African animal trypanosomiasis, a wasting disease of cattle and other livestock that is arguably Africa’s most devastating livestock disease.

In addition, both trichinellosis (caused by eating undercooked pork infected by the larva of a roundworm) and toxoplasmosis (caused by a protozoan pathogen through ingestion of cat faeces or undercooked meat) are ‘very real threats to these free-ranging pigs, with access to kitchen waste, in particular meat products, being a risk factor for infection. Such swill is also implicated in ASF transmission’.

While confining pigs would clearly be advantageous for all of these reasons, the practice of free range will likely be hard to displace, not least because this low-input system is within the scarce means of this region’s severely resource-poor farmers. Local extension services, therefore, will be wise to use carrots as well as sticks to persuade farmers to start ‘zero-scavenging’ pig husbandry, Fortunately, as this study indicates, they can do this by demonstrating to farmers the economic as well as health benefits they will accrue by penning, and pen-feeding, their free-ranging pigs.

Scavenging pigs in Busia, western Kenya (photo credit: ILRI/Charlie Pye-Smith).

Project funders
This research was supported by the Wellcome Trust, BBSRC (Biotechnology and Biological Sciences Research Council) and MRC (Medical Research Council), all of Great Britain. It is also an output of a component of the CGIAR Research Program on Agriculture for Nutrition and Health investigating Agriculture-Associated Diseases.

Read the whole paper
The spatial ecology of free-ranging domestic pigs (Sus scrofa) in western Kenya, by Lian Thomas, William de Glanville, Elizabeth Cook and Eric Fèvre, BMC Veterinary Research 2013, 9:46. doi: 10.1186/1746-6148-9-46

Article URL
http://www.biomedcentral.com/1746-6148/9/47 The publication date of this article is 7 Mar 2013; you will find here a provisional PDF; fully formatted PDF and full text (HTML) versions of the paper will be available soon.

About the project
Begun in 2009 and funded by the Wellcome Trust, with other support from ILRI, this project has studied neglected zoonotic diseases and their epidemiology to raise levels of health in poor rural communities. The project, People, Animals and their Zoonoses (PAZ), is based in western Kenya’s Busia District and is led by Eric Fèvre, who is on joint appointment at ILRI and the University of Edinburgh. More information can be found at the University of Edinburgh’s Zoonotic and Emerging Diseases webpage or on ILRI’s PAZ project blog site.

The May 2010 issue of the Veterinary Record gives an excellent account of this ambitious human-animal health project: One medicine: Focusing on neglected zoonoses.

Related stories on ILRI’s AgHealth, Clippings and News blogs
Tracking of free range domestic pigs in western Kenya provides new insights into dynamics of disease transmission, 22 Mar 2013.
Aliens in human brains: Pig tapeworm is an alarming, and important, human disease worldwide, 23 May 2012.
Forestalling the next plague: Building a first picture of all diseases afflicting people and animals in Africa, 11 Apr 2011. This blog describes an episode about this project broadcast by the Australian science television program ‘Catalyst’; you can download the episode here: ABC website (click open the year ‘2011’ and scroll down to click on the link to ‘Episode 4’; the story starts at 00.18.25).
Edinburgh-Wellcome-ILRI project addresses neglected zoonotic diseases in western Kenya, 28 Jul 2010.

Short film illustrates expanded, agile partnerships behind recent disease research breakthrough

Posted on June 20, 2011 by Susan MacMillan

This short (5-minute) film, ‘Battling a Killer Cattle Disease’, produced by the International Livestock Research Institute (ILRI), provides background and context for a recent research breakthrough made at ILRI’s animal health laboratories in Nairobi, Kenya, and at their partner institutions in the UK and Ireland. The research was funded over 7 years in large part by the Wellcome Trust in addition to the Consultative Group on International Agricultural Research (CGIAR).

Trypanosomosis is a wasting disease of livestock that maims and eventually kills millions of cattle in Africa and costs the continent billions of dollars annually.

In 2011, a group of geneticists at these collaborating institutions identified two genes that enable Africa’s ancient N’Dama cattle breed to resist development of the disease trypanosomosis when infected with the causative, trypanosome, parasite.

The team members were able to make use of the latest gene mapping and genomic technologies because they had the genetic systems and experimental populations of livestock in place to do so as these technologies came on stream.

Eventually, these results should make it easier for livestock breeders in Africa to breed animals that will remain healthy and productive in areas infested by the disease-carrying tsetse fly.

The international team that came together in this project is an example of the disciplinary breadth as well as agility needed to do frontline biology today. In this work, the team developed several new research approaches and technologies that were needed to unravel some fundamental biological issues, with likely benefits for many African farmers and herders.

Those interviewed in the film include Harry Noyes, at the University of Liverpool; Alan Archibald, at the Roslin Institute at the University of Edinburgh; Andy Brass, at the University of Manchester; and Steve Kemp and Morris Agaba, at ILRI.

Scientists identify livestock genes to unlock protection against one of Africa’s oldest animal plagues

Posted on May 18, 2011 by Susan MacMillan

Cow suffering from trypanosomiasis (photo credit: ILRI/Elsworth).

An international research team using a new combination of approaches has found 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 size of the United States. The team’s results were published today in the Proceedings of the National Academy of Sciences (PNAS).

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.

With increased surveillance and control, sleeping sickness infections in people have dropped ten-fold in the last 13 years, from an estimated 300,000 cases a year in 1998 to some 30,000 in 2009, with the disease eventually killing more than half of those infected. 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 US$4–5 billion.

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.

‘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.

This genetics of disease resistance research was led by scientists from ILRI in Africa and from the UK universities of Liverpool, Manchester and Edinburgh, and involved researchers from other institutions in Britain, Ireland and South Korea.

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. Having been domesticated in Africa some 8,000 or more years ago, this most ancient of African breeds has had time to evolve resistance to the parasites. This makes the N’Dama a valued animal in Africa’s endemic regions. On the other hand, N’Dama cattle tend to be smaller, to produce less milk, and to be less docile than their bigger, humped cousins.

African agriculturalists of all kinds would like to see the N’Dama’s inherent disease resistance transferred to these other more productive breeds, but this is difficult without precise knowledge of the genes responsible for disease resistance in the N’Dama. Finding these genes has been the ‘Holy Grail’ of a group of international livestock geneticists for more than two decades, but the genetic and other biological pathways that control bovine disease resistance are complex and have proven difficult to determine.

The PNAS paper is thus a landmark piece of research in this field. The international and inter-institutional team that made this breakthrough did so by combining a range of genetic approaches, which until now have largely been used separately.

‘This may be the first example of scientists bringing together different ways of getting to the bottom of the genetics of a very complex trait,’ said Kemp. ‘Combined, the data were like a Venn diagram overlaying different sets of evidence. It was the overlap that interested us.’

They used these genetic approaches to distinguish differences between the ‘trypano-tolerant’ (humpless) N’Dama, which come from West Africa, and ‘trypano-susceptible’ (humped) Boran cattle, which come from Kenya, in East Africa. The scientists first identified the broad regions of their genomes controlling their different responses to infection with trypanosome parasites, but this was insufficient to identify the specific genes controlling resistance to the disease. So the scientists began adding layers of information obtained from other approaches. They sequenced genes from these regions to look for differences in those sequences between the two breeds.

The team at Edinburgh conducted gene expression analyses to investigate any differences in genetic activity in the tissues of the two cattle breeds after sets of animals of both breeds were experimentally infected with the parasites. Then, the ILRI group tested selected genes in the lab. Finally, they looked at the genetics of cattle populations from all over Africa.

Analyzing the vast datasets created in this research presented significant computational challenges. Andy Brass and his team in the School of Computer Science at the University of Manchester managed to capture, integrate and analyze the highly complex set of biological data by using workflow software called ‘Taverna,’ which was developed as part of a UK e-Science initiative by Manchester computer scientist Carole Goble and her ‘myGrid’ team.

‘The Taverna workflows we developed are capable of analyzing huge amounts of biological data quickly and accurately,’ said Brass. ‘Taverna’s infrastructure enabled us to develop the systematic analysis pipelines we required and to rapidly evolve the analysis as new data came into the project. We’re sharing these workflows so they can be re-used by other researchers looking at different disease models. This breakthrough demonstrates the real-life benefits of computer science and how a problem costing many lives can be tackled using pioneering E-Science systems.’

To bolster the findings, population geneticists from ILRI and the University of Dublin examined bovine genetic sequences for clues about the history of the different breeds. Their evidence confirmed that the two genes identified by the ILRI-Liverpool-Manchester groups were likely to have evolved in response to the presence of trypanosome parasites.

‘We believe the reason the N’Dama do not fall sick when infected with trypanosome parasites is that these animals, unlike others, have evolved ways to control the infection without mounting a runaway immune response that ends up damaging them,’ said lead author Harry Noyes, of the University of Liverpool. ‘Many human infections trigger similarly self-destructive immune responses, and our observations may point to ways of reducing such damage in people as well as livestock.’

This paper, said Kemp, in addition to advancing our understanding of the cascade of genes that allow Africa’s N’Dama cattle to fight animal trypanosomiasis, reaffirms the importance of maintaining as many of Africa’s indigenous animal breeds (as well as plant/crop varieties) as possible. The N’Dama’s disease resistance to trypanosome parasites is an example of a genetic trait that, while not yet fully understood, is clearly of vital importance to the continent’s future food security. But the continued existence of the N’Dama, like that of other native ‘niche’ African livestock breeds, remains under threat.

With this new knowledge of the genes controlling resistance to trypanosomiasis in the N’Dama, breeders could screen African cattle to identify animals with relatively high levels of disease resistance and furthermore incorporate the genetic markers for disease resistance with markers for other important traits, such as high productivity and drought tolerance, for improved breeding programs generally.

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.

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See this news and related background material at ILRI’s online press room.

The International Livestock Research Institute (www.ilri.org) works with partners worldwide to help poor people keep their farm animals alive and productive, increase and sustain their livestock and farm productivity, and find profitable markets for their animal products. ILRI’s headquarters are in Nairobi, Kenya; we have a principal campus in Addis Ababa, Ethiopia, and 13 offices in other regions of Africa and Asia. ILRI is part of the Consultative Group on International Agricultural Research (www.cgiar.org), which works to reduce hunger, poverty, illness and environmental degradation in developing countries by generating and sharing relevant agricultural knowledge, technologies and policies. This research is focused on development, conducted by a Consortium (http://consortium.cgiar.org) of 15 CGIAR centres working with hundreds of partners worldwide, and supported by a multi-donor Fund (www.cgiarfund.org).

The University of Liverpool (www.liv.ac.uk) is a member of the Russell Group of leading research-intensive institutions in the UK. It attracts collaborative and contract research commissions from a wide range of national and international organizations valued at more than £110 million annually.

The University of Manchester (www.manchester.ac.uk), also a member of the Russell Group, is the largest single-site university in the UK. It has 22 academic schools and hundreds of specialist research groups undertaking pioneering multi-disciplinary teaching and research of worldwide significance. According to the results of the 2008 Research Assessment Exercise, the University of Manchester is now one of the country’s major research universities, rated third in the UK in terms of ‘research power’. The university has an annual income of £684 million and attracted £253 million in external research funding in 2007/08.

Assessing animal diseases: New paper urges use of value chain analysis and information economics to understand animal disease impacts

Posted on September 29, 2010 by Paul Karaimu

Cows standing in the compound after grazing in Chokwe, Mozambique. A new study calls for improved integration between epidemiology and economics to understand economic and poverty impacts of animal diseases (photo credit: ILRI/Mann)

A new study by researchers working with the International Livestock Research Institute (ILRI) is recommending use of ‘bottom-up’ approaches that use the strengths offered by value chain analysis and information economics in assessing the impacts of animal diseases and their interaction with socio-economic and institutional factors in developing countries.

Authors Karl Rich, from the Norwegian Institute of International Affairs (NUPI) and on joint appointment with ILRI and Brian Perry, an honorary professor of veterinary medicine at the Universities of Edinburgh and Pretoria and formerly a leader of ILRI’s research team on animal health and food safety for trade, say economists and epidemiologists need to work more closely in assessing the impact of animal diseases. They recommend use of ‘participatory disease surveillance’ approaches that feature models of disease assessment that consider the context in which animal diseases occur and how they affect markets, livelihoods and poverty reduction especially in developing countries where livestock serve diverse commercial and cultural roles which affect disease control efforts.

In a paper ‘The economic and poverty impacts of animal diseases in developing countries: New roles, new demands for economics and epidemiology’ published in the 15 September 2010, online edition of the Preventative Veterinary Medicine journal, the scientists say both value chain analysis and information economics hold particular promise and relevance towards animal disease impact assessment.

They note that ‘normative’ approaches that try to guide how agents affected by diseases should behave (for example by emphasizing elimination of disease while relegating issues of disease mitigation, equity, gender and poverty) have had limited success in reducing poverty and disease prevalence in developing countries. The scientists suggest that new models that consider the context decision makers, farmers and value chain actors face in the event of animal disease outbreaks and what they actually do (not only what they should do) will contribute to more effective pro-poor policymaking.

The paper also recommends harmonizing divergent incentives among different stakeholders in developing countries noting that, for example, integrating the views of political economy and institutions engaged in animal health research will help to focus more broadly and systematically on incentives and the behaviour of those institutions and political actors, thereby helping researchers to better understand the economic impact of diseases.

The paper reviews the livelihoods and poverty impacts of animal diseases in the developing world, with a focus on Rift Valley fever, highly pathogenic avian influenza (HPAI) and foot and mouth disease. The paper also analyses the effects of these diseases through a poverty and value chains perspective and highlights ways that lessons from these perspectives can be aligned with disease control initiatives.

Rift Valley fever outbreaks are common in eastern Africa, especially after heavy rains, which lead to rises in numbers of mosquitoes that spread this viral zoonotic disease. Rift Valley fever affects cattle, sheep, goats and camels but also infects and kills humans. A recent outbreak of the disease between 2006 and 2007 killed more than 100 people in Kenya and led to significant loss of animals and livelihoods, especially for pastoralist livestock keepers.

Rich and Perry say the response of different stakeholders to diseases is based on their unique circumstances and constraints and their incentive for compliance also depends on such contexts. Their paper stresses the importance of ‘improved integration between epidemiology of disease and its relationships with economic behaviour.’

The authors call for a holistic look at the livestock sector as a system of interacting actors, each with their own values and constraints. They say that frameworks such as those offered by value chains can help identify the impacts that animal diseases generate. The value chain framework’s emphasis on relationships, characteristics and dynamics among actors, can help identify not only who is impacted by animal disease but also how and why they are affected and how different actors might behave and adjust in response to disease outbreaks.

To read the complete paper and its recommendation, click here

This piece is adapted from an original story posted on the Market Opportunities Digest blog written by Tezira Lore, communications specialist for ILRI’s Markets Theme.

Edinburgh-Wellcome-ILRI project addresses neglected zoonotic diseases in western Kenya

Posted on July 28, 2010 by Paul Karaimu

‘Neglected diseases are diseases of neglected peoples’—Eric Fèvre

Animals and people live close together throughout the developing world. Chickens, goats, pigs, cows and other farmed animals range freely in and out of rural homesteads as families go about their daily lives. This space-sharing by people and their livestock makes good use of the small plots of land managed by the world’s many smallholder farmers; food that might otherwise go to waste can be fed to the animals, for example, while animal manure feeds the cropland by fertilizing it. Most of the world’s smallholder farmers depend on their animals for milk, meat and eggs to feed their families, with the surplus generating much-needed regular household income.

However, such close proximity to their animals puts many people at risk of ‘zoonotic’ diseases, which are those transmitted between people and animals. Remarkably, more than 60% of all human diseases are infections they can get from animals and more than 70% of today’s emerging diseases, such as bird flu, are zoonotic.

Because human and animal health are particularly intertwined in poor countries where people and livestock live in such close proximity, efforts to improve human health in the developing world need to focus on improving animal as well as human health. This makes it necessary for medical and veterinary experts to collaborate and for livestock farmers and herders to be made aware of the disease risks their animals pose to the health of their households.

A project begun in 2009 and funded by the Wellcome Trust, with other support from the International Livestock Research Institute (ILRI), is studying neglected zoonotic diseases and their epidemiology to raise levels of health in poor rural communities. The project, People, Animals and Their Zoonoses, is based in Kenya’s Busia District, which sits on the country’s western border, with Uganda.

Eric Fèvre, who is working jointly for the International Livestock Research Institute (ILRI) and the University of Edinburgh, is the project’s principal investigator and leader. Fèvre says this study is important.

‘Zoonotic diseases are a great burden on poor communities’, Fèvre says. ‘In a poor household where animals and people are in regular close contact, there is a significant chance of zoonotic diseases spreading. Typically in such areas, animals have access to human waste, there is little preventative health services for livestock and there is poor-quality food and forage for people and animals.’

With insufficient and/or unreliable health infrastructure and with many poor people not readily seeking professional medical attention, these diseases often go underreported or misdiagnosed. Complicating and aggravating this already serious health situation, he says, is that ‘in some cases, other non-zoonotic infections may already be present.’

Furthermore, as reported in the May 2010 issue of Veterinary Record, Fèvre says:

‘While malaria is undoubtedly a very serious health issue, its overdiagnosis hides many other problems. To compound this, people in marginalised communities can easily fall off the policy radar – many may be born, live and die without official record being made of them and, as such, they have a weak, or nonexistent, political voice. Thus, while the diseases are grouped as “neglected zoonotic diseases,” it would be equally correct to identify them as “diseases of neglected populations”.’

The Kenya zoonotic study is a four-year project that brings together ILRI scientists in Kenya with researchers from the School of Biological Sciences at the University of Edinburgh and from the Kenya Medical Research Institute, the latter of whom are already working in much of Kenya’s Western and Nyanza provinces. These epidemiologists, veterinarians, medical health professionals and laboratory technologists will visit over 500 homesteads in Busia to collect data and samples from people and livestock; those people found ill will be treated or referred to specialists.

The project data will be used to quantify the place of zoonoses in the context of other infectious diseases and to refine our understanding of factors that put people and livestock at risk. The study team also aims to come up with diagnostic tests that can be used in the field and to design cheap, easy-to-implement health interventions for both people and livestock. The project is focusing on bovine tuberculosis, cysticercosis, brucellosis, Q-fever, Rift Valley fever and trypanosomiasis (in cattle) /sleeping sickness (in people) and their impacts on both livestock and the people.

The results of this project are expected not only to improve the health aspects of the relationship between people and their livestock in western Kenya but also to provide important background for future research and policymaking on zoonotic issues.

More information can be found at www.zoonotic-diseases.org

The May 2010 issue of the Veterinary Record gives an excellent account of this ambitious human-animal health project: http://veterinaryrecord.bvapublications.com/misc/about.dtl (subscription required).

New project to reduce chicken disease in Ethiopia

Posted on July 5, 2010 by Paul Karaimu

A new study of genetic resistance to disease in Ethiopia’s indigenous chicken breeds is scheduled to start later this year. In collaboration with the Ethiopian Institute for Agricultural Research, the University of Liverpool, Roslin Institute, the Univerisity of Edinburgh and the University of Nottingham, researchers from the International Livestock Research Institute (ILRI) will seek to identify ‘the causes of infectious diseases that have a major impact on poultry production in Ethiopia.’

Scheduled to start in September 2010, the study will take place in the district of Jarso, in eastern Ethiopia, and in Horro, in the west of the country. The results of this research will be linked to an ongoing poultry breeding program to improve resistance to ‘priority infectious diseases’ and thereby enhance the productivity of the country’s poultry sector.

Poultry play important economic, nutritional and socio-cultural roles in the livelihoods of poor rural households in Ethiopia and many other developing countries, where birds are widely integrated into smallholder production systems and help households cope with hunger and poverty.

Buying and rearing poultry is often a first step out of poverty. Women tend to own and manage chickens, usually native chicken varieties, which provide them with their only independent source of cash income.

Although breeding programs for local chickens have shown that rapid improvement in productivity is possible, researchers have yet to identify and select the optimal breeds for improving, by, for example, providing resistance to common infectious diseases.

Tadelle Dessie, a team leader of ILRI’s biotechnology theme in Ethiopia, and one of the leaders of the chicken project, says ‘enhanced genetic resistance through selective breeding is still an under-exploited low-cost opportunity for disease control in low-input poultry production systems’. He says the study will investigate genetic variability in the resistance of local chicken ecotypes to major infectious diseases hurting village poultry production in Ethiopia. Results of the research will inform strategies for improving both disease resistance and productivity.

Indigenous chicken varieties are well adapted to local environments, but local birds tend to grow slowly and produce fewer and smaller eggs than commercial varieties. Infectious diseases, however, can wipe out flocks of exotic, higher-producing, poultry.

Knowledge from this study should enable Ethiopian policymakers and animal health professionals to design more precise disease-control plans. The study itself should help improve Ethiopia’s scientific capacity in this field by training local scientists and enhancing laboratory facilities for poultry testing.

Staff are now being recruited for the project, which will be launched in September.

Serengeti surely SHALL die if a proposed highway bisects its northern wilderness—and if its human neighbours remain poverty-stricken

Posted on June 20, 2010 by Susan MacMillan

Zebra and wildebeest in Kenya’s Masai Mara Game Reserve (photo credit: ILRI/Elsworth).

The New York Times and other media are reporting this week that one of the greatest wildlife spectacles on earth—the annual migration of nearly 2 million wildebeest and zebra from the drying savannas of the Serengeti, in Tanzania, to the wetter, greener, pastures of Kenya’s adjacent Masai Mara, and back again—is threatened by a proposed new national transit road for northern Tanzania that would cut right across the migration route of these vast herds of ungulates, likely leading to the collapse of this migration and possibly the crash of this ecosystem as a whole.

Kenya’s Masai Mara is the only year-round water source in the Greater Serengeti, and thus serves as critical dry-season grazing grounds for these vast herds of big mammals.

Just one of the problems such a road would bring is a greater disease burden to people, livestock and wildlife alike. In her extensive and useful research notes to her recent article, ‘Road Kill in the Serengeti’, in the New York Times, Olivia Judson refers readers to a scientific paper written by Eric Fevre, of the Zoonotic and Emerging Diseases research group at the University of Edinburgh, now based at the International Livestock Research Institute (ILRI) in Kenya while working on a 3-year human-animal disease research project in Busia District. Fevre describes the spread of animal diseases through animal transportation in his article, ‘Animal movements and the spread of infectious diseases’ (Trends in Microbiology, 2006).

Perhaps just in time, just this month former ILRI ecologist Robin Reid, now director of the Center for Collaborative Conservation at Colorado State University, in Fort Collins, USA, began a project in Kenya that is putting radio collars on wildebeest to learn more precisely what routes the animals take in their migration. This project’s members are involving Maasai schoolchildren, who are naming the wildebeest, which they will then be able to follow. The wildebeest collars send regular tracking signals to Safaricom, which are then sent to Colorado, where the routes are posted on a web map that the schoolchildren can follow.

This year’s annual wildebeest migration has already begun. Herds are reported to have crossed the common border of Kenya/Tanzania from Northern Serengeti into Masai Mara, about 4 days ago. ‘What has been unusual about this year’s migration,’ says Paul Kirui, in the Masai Mara, ‘is that the main migration from the south arrived in the Mara early ahead of the Loita herds—the Kenyan resident herds of wildebeest—which usually migrate into the Mara from the east of the park. Normally when we start seeing them move into the park, it is a sign that the main migration from the south is on the way.’

The first population of wildebeest that Reid’s team darted and then tagged with radio collars in the Mara is the Loita group that remains resident in Kenya all year round. Or so the researchers think. The radio collars, now fixed on the first 15 wildebeest, have already started to report back and will be letting scientists, and those schoolchildren, know just where they go, and when.

Reid’s return gave ILRI cause to revisit two remarkable films about her ILRI research in the Mara. Counting in a Disappearing Land (ILRI, 11 minutes, 2007) describes Reid’s project with a Maasai community that has traditionally herded their livestock in Kenya’s wildlife-rich Masai Mara region. This ILRI project was looking to find ways of balancing the needs of people, lands and wildlife. In The Great Migration (CBS ’60 Minutes’, 15 minutes, October 2009), Scott Pelley interviews Reid about the threats to this natural spectacle and the part local Masai are playing to address these threats.

Collaborative conservation may indeed be the answer to saving the Serengeti ecosystem. Protecting majestic wild places and the wildlife they support, places that instill wonder in us, matters, of course, but so does protecting millions of people from severe poverty, chronic hunger and the afflictions that come in their wake: disease and untimely death.

With a large percentage of its land area under protection, Tanzania is a world leader in biodiversity conservation. It is also very, very poor. How this tug at resources—whether the Serengeti Plains will be used for wildlife tourism or other kinds of commerce—will play out may depend on how much the local communities living in poverty near the wildlife benefit from saving this, the last of the great migrations of big mammals on Earth.

More . . . (New York Times, 15 June 2010)

An alternative, southern road in Tanzania is discussed on a webpage of the Frankfurt Zoological Society.

See Paul Kirui’s blog on 17 June 2010 the migration on Masai Mara Updates.

Scottish and Kenyan research groups collaborate to improve control of deadly cattle disease in Africa

Posted on February 17, 2010 by MNjiru

New project launched to investigate how immunity develops in cattle to fatal diseases caused by different strains of tick-borne parasites

More than 1 in 5 people in sub-Saharan Africa live below the poverty line. Many of these people live in rural communities heavily dependent on livestock for their livelihoods. One of the most important diseases of cattle in this region is East Coast fever, a lethal infection of cattle caused by the tick-borne parasite Theileria parva. This disease afflicts cattle populations in 16 countries across eastern, central and southern Africa and is the most economically important cattle disease in 11 of these countries. Losses due to East Coast fever exceed US$300 million annually. Imported high-yielding breeds of cattle, which are increasingly being used to satisfy increasing demands for milk in this region, are particularly susceptible to this disease.

Although East Coast fever can be controlled by treating infected animals with anti-parasitic drugs and by regularly spraying or dipping animals with anti-tick chemicals, these methods are difficult to apply and costly for poor livestock keepers. Vaccination offers a more sustainable means of controlling the disease.

Cattle can be immunized against the disease by infecting them with live parasites while simultaneously treating the animals with long-acting antibiotics. Because several strains of the parasite exist in the field, this vaccination comprises a mixture of strains. A vaccine cocktail mixing three parasite strains is being used successfully in some endemic countries, but applying this so-called ‘live vaccine’ remains hindered by difficulties in maintaining the quality of the vaccine material and in finding ways to distribute the vaccine, which needs to be kept cold, cost-effectively to widely dispersed cattle herders. In addition, it remains uncertain whether the current mix of parasite strains in the vaccine is optimal for obtaining robust immunity.

Recent studies of East Coast fever have shown that the so-called ‘protective’ proteins of the causative parasite—that is, the antigenic molecules that are recognized by the T lymphocytes of the bovine immune system and thus help animals fight development of disease—vary among the different strains of the parasite that exist in the field. This project will build on these advances to investigate the nature and extent of variability in these antigens between parasite strains. This knowledge will help scientists understand the factors that determine which parasite strains induce protective immune responses in animals that have been vaccinated.

Results of the project should provide methods for maintaining high quality of the current live vaccine and identifying parasite strains that could be incorporated into an improved second-generation live vaccine. The information should also help researchers design new, genetically engineered, vaccines, which comprise not whole parasites but rather antigenic molecules of the parasite—and thus are safer, cheaper and easier to distribute than the current live vaccine.

‘This is an important project for us,’ said Philip Toye, a vaccine developer from International livestock Research Institute (ILRI). ‘The information we expect to generate will greatly increase our understanding of the current live vaccine that is being used to protect animals against East Coast fever. We can use this information to get this vaccine into wider use in the region.’

This project is being conducted jointly by scientific groups at the universities of Edinburgh and Glasgow, in Scotland, and at ILRI, in Nairobi. The project is part of a new initiative called Combating Infectious Diseases of Livestock in Developing Countries funded by the UK’s Biotechnology and Biological Services Research Council, the UK Department for International Development and the Scottish Government. ILRI’s research in this area is also supported by members of the Consultative Group on International Agricultural Research.

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