Livestock diseases contribute to an important set of problems within livestock production systems. These include animal welfare, productivity losses, uncertain food security, loss of income and negative impacts on human health. Livestock disease management can reduce disease through improved animal husbandry practices. These include: controlled breeding, controlling entry to farm lots, and quarantining sick animals and through developing and improving antibiotics, vaccines and diagnostic tools, evaluation of ethnotherapeutic options, and vector control techniques.
Livestock disease management is made up of two key components:
Prevention (biosecurity) measures in susceptible herds
Control measures taken once infection occurs.
The probability of infection from a given disease depends on existing farm practices (prevention) as well as the prevalence rate in host populations in the relevant area. As the prevalence in the area increases, the probability of infection increases.
Preventing diseases entering and spreading in livestock populations is the most efficient and cost-effective way of managing disease (Wobeser, 2002). While many approaches to management are disease specific, improved regulation of movements of livestock can provide broader protection. A standard disease prevention programme that can apply in all contexts does not exist. But there are some basic principles that should always be observed. The following practices aid in disease prevention:
Elaboration of an animal health programme
Select a well-known, reliable source from which to purchase animals, one that can supply healthy stock, inherently vigorous and developed for a specific purpose. New animals should be monitored for disease before being introduced into the main flock
Good hygiene including clean water and feed supplies
- Precise vaccination schedule for each herd or flock
Observe animals frequently for signs of disease, and if a disease problem develops, obtain an early, reliable diagnosis and apply the best treatment, control, and eradication measures for that specific disease
Dispose of all dead animals by burning, deep burying, or disposal pit
Maintain good records relative to flock or herd health. These should include vaccination history, disease problems and medication.
Surveillance and Control Measures
Disease surveillance allows the identification of new infections and changes to existing ones. This involves disease reporting and specimen submission by livestock owners, village veterinary staff, district and provincial veterinary officers. The method used to combat a disease outbreak depends on the severity of the outbreak. In the event of a disease outbreak the precise location of all livestock is essential for effective measures to control and eradicate contagious viruses. Restrictions on animal movements may be required as well as quarantine and, in extreme cases, slaughter. The pictures above illustrate the holistic approaches to livestock disease prevention and control: The left picture shows a woman and a man participataing in a rural training course in learning how to improve the health of their goats in Sudan. The right picture shows a man immunising a goat in Bangladesh.
The Technology and its Contribution to Adaptation
The major impacts of climate change on livestock diseases have been on diseases that are vector-borne. Increasing temperatures have supported the expansion of vector populations into cooler areas. Such cooler areas can be either higher altitude systems (for example, livestock tick-borne diseases) or more temperate zones (for example, the outbreak of bluetongue disease in northern Europe). Changes in rainfall pattern can also influence an expansion of vectors during wetter years and can lead to large outbreaks. Climate changes could also influence disease distribution indirectly through changes in the distribution of livestock. Improving livestock disease control is therefore an effective technology for climate change adaptation.
Benefits of livestock disease prevention and control include: higher production (as morbidity is lowered and mortality or early culling is reduced), and avoided future control costs. When farmers mitigate disease through prevention or control, they benefit not just themselves but any others at risk of adverse outcomes from the presence of disease on that operation. At-risk populations include residents, visitors and consumers. The beneficiaries might also include at-risk wildlife populations surrounding the farm that may have direct or indirect contact with livestock or livestock-related material.
Management options may interact, so the use of one option may diminish the effectiveness of another. Another critical issue is the long-term sustainability of currently used strategies. Chemical intervention strategies such as antibiotics or vaccines are not biologically sustainable. Animals develop resistance to drugs used to control certain viruses and with each new generation of vaccine a new and more virulent strain of the virus can arise (Tanji and Kielen, 2002). Small-scale producers may be negatively affected by livestock disease management if the full cost of the disease management programme is directly passed onto them with no subsidy from the government (FAO, 2003a).
Livestock disease management costs include: testing and screening, veterinary services, vaccines, training of livestock keepers and veterinary staff, and perhaps changes to practices and facilities to reflect movement restrictions and quarantines when animals are added to the herd.
Prevention and control costs are generally evaluated against expected financial losses resulting from a disease outbreak in a cost-benefit analysis. The assumption is that increased prevention and control costs lower the expected losses by diminishing the expected scale of an infection. McInerney et al (1992) present the problem graphically as a cost minimisation problem:
min C = L + E
Where C is total annual disease cost, L is the value of output losses, and E is the control expenditures (which themselves are a function of inputs purchased for control).
Knowledge and Monitoring Requirements
In order for producers to make decisions regarding disease management, they must understand the options that they have. These options depend on disease biology, prevention techniques, tests for infection and their costs, treatments available, market reactions, as well as industry and government programmes and policies. Disease biology includes transmission modes and rates, disease evolution (for example, length of time to infectious period), production losses associated with the disease, and mortality rate (where applicable).
Practical training for farmers should include:
Principles of anatomy and physiology of the livestock animals
- Principles of nutrition and pasture ecology
- Animal diseases of local importance: clinical and post mortem signs, epidemiology, prevention, treatment. Applying first aid, the use of basic veterinary medicines (wound treatments, dips, anthelmintics, antibiotics, trypanocides, babesiacides, vaccines, care and storage of medicines and vaccines, and the use and care of syringes)
- The basic principles of sero-surveillance campaigns – how to draw blood and store sera.
Modelling disease outbreaks and spread can provide valuable information for the development of management strategies. Modelling involves studying disease distribution and patterns of spread to determine the scale of a problem. This information is used to develop a model that can predict the spread of disease. Disease modelling requires prior knowledge of animal population distributions and ecology, diseases present and methods of disease transmission. Modelling can be used to assess potential disease impacts and develop contingency plans.
Geographic Information System (GIS) software can play a key role in livestock disease management. The main advantage of GIS software is not just that the user can see how a disease is distributed geographically, but also that an animal disease can be viewed against other information. For example, maps that show possible impacts of climate change on rainfall patterns, crop yields and flooding. The disease presence can then be related to these factors and more easily appreciated visually. This is important in relation to managing and responding to the changes in distribution of diseases due to changing climate (FAO, 1999). The role of indigenous knowledge in livestock disease management under climate change is shown in Figure 1 below.
Countries should cooperate in programmes against trans-boundary disease either through formally formed organisations or networks. Neighbouring countries often have similar production systems and disease risk profiles and will be more likely to be affected by similar climate change impacts in livestock disease. There will be mutual benefits and cost savings through joint preparedness planning. Public policies range from bounties/indemnities for infected livestock to required herd depopulation and farm decontamination,to decentralisation programmes for provision of veterinary services and drug supplies. Livestock and animal health policy should be oriented to both the commercial and pastoral sectors and include pro-poor interventions to support the most vulnerable populations. Government investments in infrastructure (including early warning systems, roads, abattoirs, holding pens, processing plants, air freight/ports and so on), systematic vaccination, and in research and development can all contribute to providing an enabling environment for effective livestock disease management. Removing or introducing subsidies for improved management, insurance systems and supporting income diversification practices could benefit adaptation efforts (IFAD, 2009).
A lack of strong institutions and political will to monitor disease status effectively can produce a considerable barrier to livestock disease management. Difficulties in eradication of disease may also be exacerbated by many small-scale and backyard producers, infected wildlife, smuggling, and cockfighting (FAO, 2003). If there is no compensation for stamping out disease through slaughter, then producers, particularly smallscale producers, may be reluctant to participate. If they do participate it may mean that they no longer can afford to produce (FAO, 2003).
Where the disease organism has built up resistance against vaccines or the animal has built resistance against the disease there is an opportunity for incorporating simple, high-tech genetic approaches such as selective breeding. National planning for livestock disease management also presents an opportunity to improve agricultural support services in rural areas and to incorporate indigenous knowledge into formal prevention and control plans, thereby unlocking the potential of low-cost interventions and disseminating information on traditional lessons and experiences to a wider audience. Trans-border collaboration can provide an opportunity to strengthen veterinary services and can improve the effectiveness of disease management programmes through harmonisation of prevention and control measures, such as disease reporting and surveillance.
Environmental Council of Zambia (2009) Second National Communication under the United Nations Framework Convention on Climate Change. Lusaka. Republic of Zambia. 2009
FAO (1999) Manual on Livestock Disease Surveillance and Information Systems, FAO, Rome; 1999
FAO (2003) Trade Reforms and Food Security: Conceptualizing the Linkages, Commodities and Trade Division, FAO, Rome, 2003
FAO (2003a) Project on Livestock Industrialisation, Trade and Social-Health-Environment Impacts in Developing Countries; FAO, Rome, 2003
IFAD (The International Fund for Agricultural Development) (2002) ‘The Rural Poor’ in World Poverty Report, IFAD, Rome, 2002
McInerney, J. P., K.S. Howe and J.A. Schepers (1992) “A framework for the economic analysis of disease in farm livestock.” Preventive Veterinary Medicine. 12:137-154. 1992
Niamir-Fuller, M. (1994) Women Livestock Managers in the Third World: Focus on Technical Issues Related to Gender Roles In Livestock Production, Staff Working Paper 18, Rome, IFAD, December 1994
Moonga, E. and H. Chitambo (2010) The role of Indigenous Knowledge and Biodiversity in Livestock Disease Management under Climate Change, paper presented at the 2nd International Conference: Climate, Sustainability and Development in Semi-arid Regions August 16 – 20, 2010, Fortaleza – Ceará, Brazil
Tanji, K.K. and N. C Kielen,. (2002) FAO Irrigation and Drainage Paper 61: Agricultural Drainage Water Management in Arid and Semi-Arid Areas. FAO, Rome, 2002
Wobeser, G. (2002) Scientific and Technical Review of the Office International des Epizooties 21(1), 159-178. 2002
Clements, R., J. Haggar, A. Quezada, and J. Torres (2011). Technologies for Climate Change Adaptation – Agriculture Sector. X. Zhu (Ed.). UNEP Risø Centre, Roskilde, 2011, available at http://tech-action.org/