49 research outputs found
Impact assessment of agricultural research in West Africa: An application of the propensity score matching methodology
Ex-post evaluation of agricultural research is aimed to empirically provide evidence of past investmentsâ effectiveness. This paper is intended to measure the immediate impact of livestock research activities on cattle farmersâ knowledge about trypanosomosis and its curative and preventive control strategies. According to the quasi-experimental design of the intervention, it is shown that its impact will be adequately estimated by propensity score matching (PSM). Based on data collected according to a knowledge, attitude and practice (KAP) questionnaire in the region of KĂ©nĂ©dougou that is common to Mali and Burkina Faso, results indicate a significant gain in farmersâ know-how due to participation in livestock research activities
Economic analysis of animal disease control inputs at farm level: the case of trypanocide use in villages under risk of drug resistance in West Africa
This paper presents an economic analysis of the use of drugs (isometamidium and diminazene) in controlling African Animal Trypanosomosis (AAT), a serious disease of cattle and small ruminants in villages that exhibit resistance to isometamidium in Burkina Faso and Mali in West Africa. The study applies a production function framework integrating a damage control function to assess the short term productivity effect of trypanocide use under different epidemiological conditions. We found that the marginal value products of isometamidium in all epidemiological conditions, and the marginal value product of diminazene in high-prevalence-high-resistance conditions are positive and greater than one revealing an underuse of trypanocidal drugs in those conditions. The economical optimum level of isometamidium is far larger than the current use level. In a strict economic interpretation, this implies that in the short term cattle farmers could increase the profitability if they increase trypanocide input beyond current levels. On the other hand, if the use of trypanocide increases, cattle farmers will also be more likely to experience future losses from trypanocide resistance. In this paper we demonstrated the feasibility of applying the damage control framework for measuring the productivity of veterinary therapeutic drugs at farm level in poor African countries
Disseminating research results on trypanocide resistance in West Africa: a method for identifying effective pathways
Etude des politiques relatives aux stratégies de gestion de la chimiorésistance dans le cadre de la lutte contre la trypanosomose en Afrique de l'Ouest: cas du Mali
Discussion sur lâetude des politiques relatives aux stratĂ©gies de gestion de la chimiorĂ©sistance dans le cadre de la lutte contre la trypanosomose en Afrique de lâOuest, Mali. Le projet a pour objectif dâassurer lâefficacitĂ© des trypanocides comme une composante effective des strategies intĂ©grĂ©es et amĂ©liorĂ©es de contrĂŽle de Ia trypanosomose animale dans Ia region ouest-africaine. Pour atteindre cet objectif, des organisations nationales de recherche et de developpement, des institutions internationales et rĂ©gionales de recherche, et des universitĂ©s allemandes travaillent en partenariat afin de dĂ©velopper aux niveaux local et regional des strategies de reduction de risque de Ia chimiorĂ©sistance. Lâaccent est mis principalement sur lâinformation et des supports techniques aux paysans, aux prestataires de service en sante animale, aux vĂ©tĂ©rinaires professionnels et aux dĂ©cideurs politiques. Les informations et supports techniques ont pour but de promouvoir Ia lutte intĂ©grĂ©e et lâutilisation rationnelle des trypanocides afin de rĂ©duire les risques a long terme de Ia chimiorĂ©sistance sans compromettre Ia capacitĂ© des Ă©leveurs a pouvoir protĂ©ger leurs animaux contre les effets nĂ©fastes de la trypanosomose animale. Le projet est rĂ©alisĂ© au Burkina Faso, au Mali et en GuinĂ©e par lâlnstitut International de Recherche sur lâElevage (lLRl) en collaboration avec dâautres organisations. Des approaches de solutions sont alors proposees de maniere a apporter une solution durable au phenomene de la chimioresistance
Gendered analysis of the demand for poultry feed in Kenya
The study obtained estimates of demand elasticities for common poultry feed (mixed feed, grain, and leafy vegetables) in both male-headed and female-headed households. In Kenya, poultry farming is a major livestock subsector contributing to both income and food security of households. Women form an important link between the success of the poultry enterprise and its contribution to alleviating poverty. Results of the study show that demand for mixed feed is inelastic with respect to the price of mixed feed and vegetables for both farmer categories; however, the value of elasticity (in absolute terms) for female-headed households almost doubles elasticities found for male-headed households.Australian Centre for International Agricultural Research (ACIAR)Rockefeller FoundationNetherlands Organization for Scientific ResearchWOTRO Science for Global Developmen
Distribution and diversity of the vectors of Rift Valley fever along the livestock movement routes in the northeastern and coastal regions of Kenya
BACKGROUND : Knowledge of vector ecology is important in understanding the transmission dynamics of vector
borne disease. In this study, we determined the distribution and diversity of mosquitoes along the major nomadic
livestock movement routes (LMR) in the traditional pastoral ecozone of northeastern Kenya. We focused on the
vectors of Rift Valley fever virus (RVFv) with the aim of understanding their ecology and how they can potentially
influence the circulation of RVFv.
METHODS : Mosquito surveys were conducted during the short and long rainy seasons from November 2012 to
August 2014 using CO2-baited CDC light traps at seven sites selected for their proximity to stopover points that
provide pasture, water and night bomas (where animals spend nights). We compared mosquito abundance and
diversity across the sites, which were located in three ecological zones (IV, V and VI), based on the classification
system of agro-ecological zones in Kenya.
RESULTS : Over 31,000 mosquitoes were trapped comprising 21 species belonging to 6 genera. Overall mosquito
abundance varied significantly by ecological zones and sites. Mansonia species (Ma. uniformis and Ma. africana)
were predominant (n = 12,181, 38.3 %). This was followed by the primary RVF vectors, Ae. ochraceus and Ae.
mcintoshi comprising 17.9 and 14.98 %, respectively, of the total captures and represented across all sites and
ecological zones. The Shannon diversity index ranged from 0.8 to 2.4 with significant zone, site and seasonal
variations. There was also significant species richness of RVF vector across ecological zones.
CONCLUSION : Our findings highlight differential occurrence of RVFv vectors across ecological zones and sampling
sites, which may be important in determining areas at risk of emergence and circulation of RVFv. Moreover, the
vector distribution map along LMR generated in this study will guide potential interventions for control of the
disease, including strategic vaccination for livestock.International Development Research Centreâs (IDRC) funding to icipe under the Eco-health program.http://www.parasitesandvectors.comhb201
Linking international agricultural research knowledge with action for sustainable poverty alleviation: what works?
Advances in crop insect modelling methodsâTowards a whole system approach
A wide range of insects affect crop production and cause considerable yield losses. Difficulties reside on the development and adaptation of adequate strategies to predict insect pests for their timely management to ensure enhanced agricultural production. Several conceptual modelling frameworks have been proposed, and the choice of an approach depends largely on the objective of the model and the availability of data. This paper presents a summary of decades of advances in insect population dynamics, phenology models, distribution and risk mapping. Existing challenges on the modelling of insects are listed; followed by innovations in the field. New approaches include artificial neural networks, cellular automata (CA) coupled with fuzzy logic (FL), fractal, multi-fractal, percolation, synchronization and individual/agent based approaches. A concept for assessing climate change impacts and providing adaptation options for agricultural pest management independently of the United Nations Intergovernmental Panel on Climate Change (IPCC) emission scenarios is suggested. A framework for estimating losses and optimizing yields within crop production system is proposed and a summary on modelling the economic impact of pests control is presented. The assessment shows that the majority of known insect modelling approaches are not holistic; they only concentrate on a single component of the system, i.e. the pest, rather than the whole crop production system. We suggest system thinking as a possible approach for linking crop, pest, and environmental conditions to provide a more comprehensive assessment of agricultural crop production.Peer reviewe
On-farm maize storage systems and rodent postharvest losses in six maize growing agro-ecological zones of Kenya
Rodents are one of the major postharvest pests that affect food security by impacting on both food availability and safety. However, knowledge of the impact of rodents in on-farm maize storage systems in Kenya is limited. A survey was conducted in 2014 to assess magnitudes of postharvest losses in on-farm maize storage systems in Kenya, and the contribution of rodents to the losses. A total of 630 farmers spread across six maize growing agro-ecological zones (AEZs) were interviewed. Insects, rodents and moulds were the main storage problems reported by farmers. Storage losses were highest in the moist transitional and moist mid-altitude zones, and lowest in the dry-transitional zone. Overall, rodents represented the second most important cause of storage losses after insects, and were ranked as the main storage problem in the lowland tropical zone, while insects were the main storage problem in the other AEZs. Where maize was stored on cobs, total farmer perceived (farmer estimation) storage weight losses were 11.1 ± 0.7 %, with rodents causing up to 43 % of these losses. Contrastingly, where maize was stored as shelled grain, the losses were 15.5 ± 0.6 % with rodents accounting for up to 30 %. Regression analysis showed that rodents contributed significantly to total storage losses (p < 0.0001), and identified rodent trapping as the main storage practice that significantly (p = 0.001) lowered the losses. Together with insecticides, rodent traps were found to significantly decrease total losses. Improved awareness and application of these practices could mitigate losses in on farm-stored maize
Economic analysis of trypanocide use in villages under risk of drug resistance in West Africa.
Economic analysis can assist in the understanding of the factors that determine the success of trypanosomosis control by cattle farmers in the cotton zone of West Africa. Trypanocides are the most widely used method of control, and determining their short- and long-term productivity
provides important information. However, this must be interpreted in the light of emerging drug resistance, which poses a major obstacle to the sustainability of drug use. More generally, this research aims to advance the methodology of measuring the productivity of animal disease control
inputs in West African cattle production. The study includes an empirical assessment of the productivity of trypanocidal drugs and the costs of trypanosomosis under village conditions. The analysis was extended to capture the implications for the livelihood of the poor cattle farmers of a
declining susceptibility of trypanosomes to drugs. The results of this research can help decisionmakers to put in place strategies for improved management of trypanosomosis and trypanocidal drug resistance.
The study was conducted in Burkina Faso and Mali from June 2003 to May 2004. Data were
collected by a team of veterinary epidemiologists, technicians and agro-economists. In all, 206 herds
with a total of 3565 cattle in eighteen villages were monitored during a period of twelve months. Input and output data were collected by enumerators posted in villages for which epidemiological conditions were assessed throughout the study period. Additional price information was collected in
local markets, abattoirs and through focus group discussions. It was found that cattle-keeping is important in both Mali and Burkina Faso; however, herds were larger in Mali. The smaller herd size in the study area compared to other parts of sub-Saharan Africa and the higher ratio of draught
animals to male adult cattle, especially in Burkina Faso, indicate a farming system more oriented towards intensive use of draught animals in crop production. The majority of cattle farmers in the study area considered trypanosomosis the most important disease of cattle, and knowledge of the cause of trypanosomosis in the study zone was relatively high compared to other parts of sub-Saharan Africa. Farmers are aware of many strategies to control the disease. However, their preferred strategy is the use of trypanocidal drugs and the majority of treatments are given by cattle farmers,
although this is not legal.
In the methodology developed, livestock production is modelled as a process in which local resources and external inputs are used to generate multiple outputs such as milk, meat, draught power, and manure, and indirect outputs including the finance and insurance functions of maintaining cattle stocks. The study applies a production function framework and integrates a damage control function to quantify cattle production output losses as well as the productivity effect of trypanocide use under different epidemiological conditions. For the estimation of the productivity of disease control inputs, a conventional Cobb-Douglas production function and a modified Cobb-Douglas function that integrates a damage abatement function were specified.
Dummy variables were used to capture the effects of disease prevalence and drug resistance, thus taking into account different epidemiological conditions. Three different specifications of the exponential damage control function were tested. The specification that includes two sources of
damage from diseases provided the best fit and was used for comparison with the Cobb-Douglas production function in the analysis. The productivity estimates of trypanocides in this study show that the damage control function provides consistently higher marginal productivity for both trypanocides (isometamidium and diminazene aceturate) in cattle production systems where disease is common and isometamidium resistance is high. However, the conventional Cobb-Douglas production function model shows that the productivity of trypanocidal drugs decreases in the
situation where trypanosomosis disease prevalence and drug resistance are both high. The results suggest that treating the damage control inputs such as trypanocides in cattle production, as yieldincreasing
inputs in the conventional framework is likely to generate misleading results.
The marginal value products of isometamidium in all epidemiological conditions, and the marginal value product of diminazene in high-prevalence-high-resistance conditions, reveal an underuse of trypanocidal drugs. In a strict economic interpretation, this implies that in the short term cattle
farmers could increase the profitability in those conditions if they increase trypanocide input beyond current levels. On the other hand, the static analysis applied in this study does not take into account
the negative externality of trypanocide resistance in the future.
If the use of trypanocide increases, cattle farmers will also be more likely to experience future losses from trypanocide resistance. To delay and even reverse the development of resistance the concept of
ârational drug useâ is recommended. Using drugs rationally entails: reducing need for drugs by disease prevention strategies; decreasing use of drugs by replacing with alternatives; ensuring drugs are given only when clinically needed; giving the appropriate drug at the appropriate dose; and
ensuring correct administration of the drug.
This study confirms that trypanosomosis is an important disease in the cotton zone of West Africa. Although drug resistance is increasing, trypanocidal drugs used are still effective against the disease. However, at the current sub-optimal level of isometamidium use, output losses are much higher â 9.8% to 22.7% of the value of output â than in a situation where isometamidium use is optimal for the epidemiological conditions. When disease control effort reaches the optimum level, output losses are much lower in all epidemiological conditions (1.3% to 1.5% of output). At the current use of trypanocidal drugs, economic losses due to trypanosomosis range from âŹ9.50 to âŹ22.00 per TLU1 and year.
The costs of trypanosomosis at the current level of disease control effort, which include the control costs and the remaining loss after control are higher than they would be if isometamidium use was at
optimal levels, in all epidemiological conditions. Currently, trypanosomosis disease costs cattle farmers âŹ13.30 to âŹ26.00 per TLU and year; however, at optimal disease control efforts, costs would be reduced to âŹ8.60 to âŹ10.10 per TLU and year, depending on epidemiological conditions. While the current costs of the disease represent on average 12% to 28% of the output derived from cattle production in the study area, costs of the disease at optimal drug usage would represent only 7% to 8% of output depending on disease prevalence and drug resistance levels. Lower costs of the disease and the increasing productivity of trypanocide in conditions of high drug resistance may create an intractable situation in which cattle farmersâ choices for trypanosomosis control measures are guided by the phenomenon of path dependency. Once this occurs, the only options for controlling the disease would be the discovery of new drugs, for which the development is prohibitively expensive, or eradication of the tsetse vector of trypanosomosis â a strategy that has never been sustainable without considerable external support. Maintaining the effectiveness of trypanocides is hence a
priority for farming systems in West Africa.
The study has demonstrated the feasibility of applying the damage control framework for measuring the productivity of animal disease control inputs at farm level in poor African countries. The model developed here concentrates on the direct effects of the disease, while the dynamic aspects of drug
resistance are included in the model a simplified manner only. To capture these dynamic processes further research is required for example to develop a bioeconomic model that integrates the impacts
of trypanosomosis on cattle farmersâ livelihoods and adequately captures the biological process of drug resistance