Plant-based solutions to integrate livestock disease control, nutrition and environmental sustainability in Africa

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Smallholder livestock production is crucial to the livelihoods of rural populations throughout Africa, but is experiencing many challenges. Climate change is making nutritional resources from grazing more unpredictable, and at the same time increasing threats from parasitic and other diseases. Investing in greater inputs to stave off these threats is out of the question for most subsistence farmers and is unsustainable. Better ways of running integrated animal-plant systems are urgently needed. To that end, this project seeks to build on successful previous work, in which targeted treatment of individual sheep and goats within a herd achieved substantial uplift in health and productivity with much lower input costs than standard whole-herd treatment. Further improvements to the system would be to replace chemical anthelmintics with plants shown to reduce parasite burdens, which grow locally and could be cultivated or sustainably harvested. Research on such plants shows a long list of candidates but evaluation of effects in the field under real farming conditions are very limited. These plants can help bridge the nutrition gap also by increasing protein availability, but assessments have rarely considered antiparasitic and nutritional benefits together, especially with native plants in Africa. We will train farmers to apply targeted selective antiparasitic treatment strategies based on established field guides for monitoring impacts of infection on health, and compare the need for treatment and the health and performance levels between herds using antiparasitic drugs only and those that integrate 'bioactive' plants species into their feeding practices. A key benefit of using plants to reduce parasite burdens is reduction of environmental contamination with infective parasite stages, and therefore general reduction in infection levels, benefitting all animals sharing grazing. Recent advances in epidemiological modelling enable rigorous evaluation of this indirect effect of plant use for the first time, as a function of climate and management, and we propose to apply those models to assess impacts under current and future climates. Models will be extended to consider where and in what seasons the evaluated interventions would be of most use, and how they should be configured to maximise resilience of smallholder production systems under current and future conditions. Finally, benefits of healthier livestock for household livelihoods are potentially immense but are hard to measure for subsistence farmers, in which improved productivity does not necessarily translate into cash profit, but has subtle effects on food and economic security. Integrated into the field trials, we plan to evaluate connections between livestock health and household wellbeing using socio-economic interviews. Outcomes will be a toolkit for application of targeted treatment approaches and nutritional intervention that makes the most of locally available plant resources, an improved evidence base for plant-focused interventions in these systems, measures of livelihood impacts within the study and potential when upscaled, and projections of epidemiological risks and benefits across Africa. As a result of this project, tools will be created for rapid evaluation of and adaptation to disease and nutrition threats throughout Africa, to support sustainable production and food security in the poorest areas.