In response to our first grant announcement, we received hundreds of applications, including one on using herbs to treat nematodes in livestock. The researcher behind it kindly agreed to explain it to our readers while it’s still under peer review.
Tiny but dangerous
West Africa faces a host of food security challenges, from conflict and adverse weather to poor infrastructure hindering farmers’ access to markets. An often-overlooked food security risk is the threat parasites pose to livestock.
Ruminants plagued by parasites can be treated with veterinary care and medicines, of course, but too often these interventions are simply not available in smallholder agricultural communities. That’s the case in much of rural Burkina Faso, where one applicant for a Grow Further research grant is fretting over losses farmers are suffering from gastrointestinal nematodes, tiny but nasty parasites that cause animals to waste away, lowering meat and milk production.
Chemical molecules are not only unaffordable to rural farmers because of their high prices and their absence in the most remote areas, but they are also increasingly ineffective.
Nematodes are microscopic animals that closely resemble worms. They’ve evolved to survive in nearly every ecosystem and can be found in soils at the peaks of mountains and at the bottom of the ocean. Several nematode species are considered beneficial to gardeners, but others are parasitic. “In particular, the Haemonchus contortus parasite is the nematode species that causes the most losses to livestock breeders because of its hematophagous diet,” Dr. Amadou Dicko at the Institute of Environment and Agriculture Research (INERA) in Burkina Faso told us in a recent interview.
Dr. Dicko said current H. contortus control practices involve treating animals with expensive chemicals that most Burkinabe herders simply can’t afford. And besides, the nematodes are evolving to resist these chemical treatments, he added, rendering this option useless in some instances.
“Indeed, these chemical molecules are not only unaffordable to rural farmers because of their high prices and their absence in the most remote areas, but they are also increasingly ineffective due to the emergence of parasite resistance in many farms around the world,” he said. “They are also ecotoxic, causing huge environmental problems.” West Africa’s smallholder pastoralists need a better solution.
An herbal remedy
Dicko is now proposing a much more cost-effective remedy—locally-grown herbs. Finding the right native plants or plant combinations that can beat back the parasitic nematodes just as effectively as chemicals can is no easy feat, but Dicko and his team are spearheading a project that they believe will do just that.
Dr. Dicko and his team told us that they’ve already identified two promising candidate targets for their study: the herbaceous plants Ceratotheca sesamoïdes, an indigenous African flowering plant, and Striga hermonthica, otherwise known as witchweed.
Striga hermonthica is a parasite in its own right. A colleague of Dr. Dicko’s is attempting to breed varieties of sorghum plants that can resist witchweed attacks. But Dr. Dicko told us that certain compounds from these two plants can be isolated to produce one or two natural drugs that can be used to treat H. contortus infections in livestock. He anticipates developing either two drugs from the two plants or a therapy with ingredients from both. Once they’ve figured out how to produce the best herbal option or options, Dicko and his team will disseminate the technology to herders.
This natural medicine “would be more accessible and less costly for the rural breeders in the sense that they are herbaceous plants well known by the breeders,” he explained. Treatments would be timed to account for the plants’ natural growing cycles and to head off gastrointestinal nematode infections. He said the candidate plants sprout during the rainy season and are natural, thereby presenting very little to no threat to the environment.
Dr. Dicko’s research shows how threats to global food security are not always visible to the naked eye. A literal homegrown remedy to counter the H. contortus threat is the sort of smallholder agriculture innovation that excites us at Grow Further. We wish Dr. Dicko and his colleagues the best of luck.
— Grow Further
Photo credit: Cattle in Burkina Faso. P. Casier, CGIAR.