Reducing the impact of infectious disease on village poultry production in Ethiopia

Poultry play an important economic, nutritional and socio-cultural role in the livelihoods of poor rural households in many developing countries, including Ethiopia, where scavenging poultry are an integrated part of the smallholder production systems and play a significant role in poverty alleviation. Chickens have a high socio-economic value and are important to those (often landless) people who do not own cattle, sheep, or goats. Poultry production is particularly important to women, who often own and manage the chickens and control cash from sales. The resulting income is often used to support education of children. Developing countries have many indigenous chicken varieties which are well adapted to local environments as they are excellent foragers, better able to avoid predator attacks and demonstrate better immunity to common diseases. However, due to relatively low genetic potential and poor levels of husbandry, most of these indigenous chicken breeds grow slowly and are poor producers of small sized eggs. Furthermore, infectious diseases have a major impact and prevent even this limited genetic potential from being realised. Breeding programmes using local chicken ecotypes suggest rapid improvement in productivity is possible. However, these programmes are yet to select for resistance to infectious disease. Enhanced genetic resistance through selective breeding represents an under-exploited low cost opportunity for disease control in low input poultry production systems. The aim of this project is to develop a poultry breeding programme to improve resistance to priority infectious diseases whilst enhancing productivity and production. Realisation of this objective requires three further overlapping objectives: (i) investigation of the genetic resistance of local poultry varieties; (ii) identification of the diseases with the greatest burden to village poultry; and, (iii) investigation of the wider social and economic impact of infectious diseases and of factors affecting uptake of control strategies. Investigation of resistance in local Ethiopian poultry will not only identify genetic regions and genes that can be used to inform cross breeding programmes in Ethiopia, but will also greatly extend our knowledge of the genetics of resistance in poultry, which to date has largely been studied in inbred and commercial poultry lines. Our study identifying the important diseases of village poultry in Ethiopia will be the first to simultaneously examine the impact of a large number of pathogens and will begin to explore how these agents act in concert to cause the diseases seen by farmers. We will also explore the cause of the major epidemics seen each year resulting in death of many birds. Together, this knowledge will enable more precise disease control planning by Ethiopian policy makers and animal health professionals, as well as inform targeting of the breeding programme. Village poultry production is undertaken by poor rural farmers with little or no input. This means that all output (eggs, meat, offspring) represent a net gain to the farmer, but also limits the potential for even low cost disease control interventions. Furthermore, poultry production is deeply imbedded in Ethiopian society and the characteristics of birds are important to the farmers. We will work with farmers to identify diseases impacting production and productivity of their birds, factors affecting uptake of control strategies (including indigenous controls) and the desirable characteristics of birds. We will utilise the results of these studies to inform selection in an ongoing breeding program which is improving the productivity of local poultry ecotypes for distribution to villages. Thus we will ensure that the improved birds also have enhanced resistance to key infectious diseases. The project will also provide a legacy of improved capacity within Ethiopia, including training of local scientists and enhanced laboratory facilities.

Poultry play an important role in the livelihood of poor rural households in many developing countries. However, infectious diseases have major impact on productivity. Selective breeding for enhanced genetic resistance represents an under-exploited low cost opportunity for disease control. The aim of this project is to develop a poultry breeding program to improve resistance to priority infectious diseases whilst enhancing productivity. Realisation of this objective requires three further overlapping objectives: 1) We will use genome-wide association studies using large numbers of SNPs and polymorphism studies at candidate resistance genes to identify the genetic components of indigenous poultry resistance/susceptibility to disease challenge. Investigation of resistance in local Ethiopian poultry will not only identify genetic regions and genes that can be used to inform cross-breeding programmes in Ethiopia, but will also greatly extend our knowledge of the genetics of resistance in poultry, which to date has largely been studied in inbred and commercial poultry lines. 2) We will identify and prioritise infectious diseases that impact on village poultry. We will use ELISA for diagnosis, in Ethiopia, of key viral and bacterial pathogens and use coprological examination to diagnose gut parasites. This knowledge will enable more precise disease control planning by Ethiopian policy makers and animal health professionals, as well as inform targeting of the breeding programme. 3) Using participatory methods we will work with farmers to identify diseases impacting poultry production, factors affecting uptake of control strategies and the desirable characteristics of birds. We will utilise all these results to inform selection in an ongoing breeding program which is improving the productivity of local poultry ecotypes for distribution to villages. Thus we should ensure that the improved birds also have enhanced resistance to key infectious diseases.

Poultry play a vital role in the livelihood of poor rural households in developing countries and are particularly important to those (often landless) people who do not other livestock and to women, who often own and manage the chickens and control cash from sales. Income from poultry production is often used to support education of children. However, low genetic potential and poor levels of husbandry mean that most indigenous breeds grow slowly and are poor producers of small eggs. Furthermore, infectious diseases prevent even this limited genetic potential from being realised, with villagers citing disease as the major limitation to production. In addition to endemic disease, outbreaks occur annually and may kill entire flocks. Ethiopian farmers often sell their flocks in anticipation of, or in the face of, such epidemics, only to later buy them back at a loss. Hence, poorly defined endemic and epidemic diseases are major impediments to productivity and impact markedly on livelihoods. This project will address these issues on several fronts in order to enable distribution of improved local poultry ecotypes with enhanced productivity and production traits as well as improved genetic resistance to important infectious diseases. Newcastle Disease has a worldwide distribution and is of enormous economic impact; Fowl Typhoid and Fowl Cholera remain important diseases of developing poultry systems, whilst coccidiosis, Marek's Disease and IBDV also remain important in developed poultry industries. Improvements in the control of these infectious diseases and of productivity of village poultry will improve the livelihoods of farmers and increase food security in Ethiopia and throughout Sub-Saharan Africa and Southern Asia. Genetic resistance to major pathogens may also have direct application to developed countries; e.g. parasitic and bacterial infections in free-range and organic poultry production are an increasing challenge and resistant breeds of poultry may provide the key to disease control. The availability of genetic information from Ethiopian poultry has considerable academic impact as a resource for study of animal genetics and evolutionary biology in particular and will be a resource available to other scientists through the Domestic Animal Genetic Resources Information System at ILRI and the Frozen Ark project at University of Nottingham. To our knowledge this is the first survey simultaneously assessing the frequency of exposure to many major pathogens and investigating the cause of major outbreaks. This will enable targeting of genetic improvement and development of strategies for disease control that utilise improved birds but also incorporate other control strategies (including technology-based strategies, such as vaccination). The role of co-infection on disease susceptibility and prevalence has been little studied in a low input production setting. This multi-pathogen approach has the potential for substantial impact in terms of knowledge and in application to disease control strategies. The socio-economic surveys enable a targeted approach to genetic improvement (based on factors important to the local communities) and to development of strategies for disease control that utilise improved birds but also recognise other (indigenous) control strategies. Crucially, this ensures that developed strategies are socially acceptable. The human and material capacity built into the proposal will have considerable impact. Two doctorate-trained researchers (plus technicians) and a laboratory equipped and skilled in diagnosis of infectious disease will play a key role in underpinning studies and disease surveillance. Through the international collaboration already built by this proposal, UK and local scientists can forge networks in Africa, the UK and the wider community that will lead to future research in genetics and infectious disease control, and in wider areas influencing animal and public health policy and strategy.