Bio-economic analysis of foot-and-mouth disease transmission between wildlife and livestock populations in Limpopo Province, South Africa

Abstract

This study contributed to the existing body of literature on the economics of smallholder livestock systems and management of conflicts between livelihood objectives of local livestock farming communities and neighbouring conservation parks in the presence of animal disease transmission such as foot-and-mouth disease (FMD). Published literature on the economics of animal disease and its control focused on a small number of developed countries, concentrating on the economic impact of animal disease on the commercial farming sector and neglecting the plight of small-scale farmers. Limiting economic analysis of animal disease to the commercial farming sector implies that the economic impact of animal disease on small-scale farmers is considered similar. In Sub-Saharan Africa, where 70% of the population is poor and depends on smallholder agricultural activities such as livestock farming for its livelihood, analysis of the economic consequences of animal disease on small-scale producers is therefore badly needed. This study investigated ways to better manage the trade-offs between keeping buffalo in the Kruger National Park (KNP) for the sake of conservation and for their recreational value and the livelihood objectives of the cattle farmers who have to contend with the transmission of FMD. Furthermore, the study assessed the factors associated with cattle herd size in the study area in order to understand the underlying reasons, challenges and opportunities for the farming community in keeping livestock. A negative binomial regression model was applied to analyse determinants of cattle ownership (eg cattle herd size) in the study area. The results of the analysis indicated that, contrary to the popular belief that rural households in developing countries own large herds of livestock for social reasons, the majority of communal livestock farmers in the study area kept livestock for economic/commercial reasons. However, limited access to marketing channels was found to be a major constraint on keeping large herds. Moreover, livestock farmers owning large herds experienced higher losses due to theft and mortality associated with diseases or predation. Given the fact that farmers in the study area keep livestock for economic reasons, but face constant challenges due to losses associated with livestock diseases, including FMD transmitted from infected buffalo from the KNP, the control of FMD could enhance the livelihood of this livestock farming community. A bio-economic model was accordingly developed to assess trade-offs between wildlife conservation and the livelihood objectives of the small-scale farmers dealing with FMD transmission (negative externality) from buffalo to cattle populations. The theoretical model was solved using optimal control techniques to evaluate the trade-off between keeping buffalo in the park and the economic impact on the livelihood objectives of the cattle farmers in the presence of the negative externality of FMD transmission. Three different scenarios, namely (1) a conservation scenario with no unified resource management policy, (2) a social planner scenario and (3) a no-disease scenario, were compared. In the model formulation it is assumed that the stock of buffalo influences the size and the composition of cattle herds through disease transmission, and ultimately the benefit and livelihood of cattle farmers, but not vice versa. Accordingly, while the conservation agency can optimise its situation without being influenced by the harvest and the cattle holding of the farmers, farmers must adjust their harvest and stocks to the stock size of buffalos. In contrast, the social planner scenario takes into consideration the interest of both agents and a socially optimal resource management policy is achieved. Analytical study results show that when the social planner allocates common resources, benefits to the farmers increase compared to the conservation scenario. While culling of buffalo is not currently practised at the park, analytical study results demonstrated that culling would be beneficial to farmers if practised in the KNP. Results of the empirical simulation analyses also confirm that when culling of buffalo is implemented, the unified management scheme (social planner scenario) would yield fewer buffalo and less disease transmission (hence fewer infected cattle), as well as higher overall economic benefits than the pure conservation scenario. An important implication of the study findings is the great potential for economic policy to enhance the welfare of smallholder cattle farmers in the country. Investment in farmers’ education and awareness of new technological innovations, appropriate measures and practices in breeding and veterinary services are proposed to be critical for improving small livestock farmers’ welfare. In addition, the study also proposes policy interventions to improve access to marketing channels and information and increased public investment in efficient game-proof fences that will effectively deter wildlife from escaping from game parks to come into contact with adjacent communal livestock, as well as more effective protection measures against theft. Results of the sensitivity analyses indicate that overall, higher benefits would be achieved when intervention measures contributing to a reduction in the proportion of buffalo that escape from the park, as well as a reduction in cattle-to-cattle transmission, are introduced simultaneously. However, comparing the two measures, investing more in preventing infection among cattle populations through quarantine and vaccination programmes would yield higher benefits to the farmers compared to decreasing FMD transmission from buffalo to cattle populations through culling of buffalos and/or increased investment in maintenance of the fence. Thus, the main policy implication of this study involves weighing up the costs and benefits of the two intervention measures. While this study assessed the impact of these interventions on farmers’ livelihood, the costs of such intervention measures were not considered, which represents a gap requiring further future research work. This study is the first to use bio-economic modelling to examine the impact of FMD on small-scale farmers within the wildlife-livestock interface in a developing economy. The model developed in this study is widely applicable to many other similar situations where transmission of animal disease from wildlife populations poses serious threats to the livelihood of small-scale livestock farmers. In addition, the policy interventions proposed in the study contribute to the search for feasible management solutions and policy measures for balancing the trade-off between environmental and economic benefits from keeping wildlife and the livelihood objectives of small-scale farmers living adjacent to conservation areas. Nonetheless, this study has limitations ranging from the simplified assumptions made to the availability of suitable data. Firstly, the optimisation model treats farmers as a homogeneous group, whereas in reality the impact in terms of benefits and costs will differ across various farmer groups depending among others on location and distance to the park. The model also incorporates non-market variables such as social status attached to cattle ownership and tourist value attached to buffalo viewing, which will require better valuation methods than the overly simplified assumptions made in this study. In addition, while the study quantifies the economic benefits of proposed FMD control measures, it does not assess the cost of such measures. While the construction of proper fencing can be expensive, there are other instruments that can be implemented to reduce the transmission between wildlife and livestock. For example, a tax on the entrance fee can be imposed, which may be used for maintaining the fence around the park.