The role of local adaptation in sustainable production of village chickens
Chickens are the most ubiquitous of livestock, with around 50 billion birds reared annually in a range of production systems ranging from the massive intensive production systems of North America, Europe and Asia though to village systems found throughout the world. Chickens are usually in the background of any television news broadcast from a rural location in a developing country. Often non-descript looking birds with brown, speckled or dark plumage, they are the unnoticed co-stars of world food production. Yet their ubiquity should be considered a sign of their adaptability and flexibility in production that allows them to be a key protein source, both from meat and eggs, and one that lends itself to increased productivity from management and genetic improvement. In the backyard system, they are often under the custody of women who control their faith as source of income and food
The research described in the paper 'The role of local adaptation in sustainable production of village chickens' is the result of a multidisciplinary project based in Ethiopia. As with many projects, it began with a corridor discussion, in this case between a veterinary epidemiologist and an avian microbiologist, and expanded to include geneticists, economists, veterinarians and more. The overarching aim of the project was to reduce the burden of infectious disease in village production systems by decreasing losses and increasing productivity. To achieve this, we needed to understand the disease challenges, the genetics of the local chicken ‘ecotypes’ reared and, crucially, the nature of the production system and the socioeconomic reasons why chickens are kept. The study was conducted in two districts (or woredas) in the Oromia region of Ethiopia. Horro, around 300 km northwest of Addis Ababa, has a predominantly orthodox Christian population and Jarso around 400 km east of Addis Ababa with a predominantly Muslim population. Sampling was conducted in four villages in each woreda over two years, with two sampling seasons prior to and following the rainy seasons. The health and disease status of two birds per household were determined through examination, blood and faecal samples. Photographs were taken to assess bird morphological features and a questionnaire on birds management completed by the household. A rapid rural appraisal involving focus groups, individual assessments with farmers and discussions with extension and development agents was undertaken prior to the main study. Diagnostic tests were performed in-country in a lab we set up at the Ethiopian Institute for Agricultural Research at Bishoftu (also called Debre Zeit). The lab became the base for the project and was able to support additional student projects and act as a hub for visits from undergraduate students from a number of Ethiopian universities. Chicken DNA samples were exported to the UK for genetic analysis.
Our expectations were that high-mortality infections such as Newcastle Disease Virus, described locally as fengele, would be a main disease challenge. Chickens would be reared as a food-source as eggs or meat in both communities and that with some local adaptation and selection that chickens would be broadly of a similar genetic background. The reality of course turn out to be more complex and varied. Rather than a single major disease challenge, a range of viral, bacterial and parasitic infections affect the health of birds and that although waves of high-mortality disease happen, these endemic diseases will lead to constant losses and reduced productivity. Reasons for keeping chickens and how they are managed were extremely varied. It was known that women play a greater role in the management of chickens than other livestock species and that they are closely associated with the household, but there is great variation in how they are managed including housing, supplementary feeding and breeding and brooding of chicks. Whilst in Horro chickens were kept more as a food source or for sale, in Jarso, chickens were kept more for social and cultural reasons. Despite more management of flocks in Horro, mortality rates were apparently higher. The genetics of the village chickens showed high levels of co-adaptation to their local ecosystems, resistance to disease and to the management and cultural variations of their environment. Beside, the data suggest that there have been multiple introductions of chickens in Ethiopia that may relate to trade routes, religion and culture. In others words multiple history of chicken husdandry. In particular, he chicken populations of Jarso and Horro are genetically distinct and the genetic evidence can allow us to speculate that they may have followed the trade routes that match the arrival of religion, with Jarso birds related to those from the Arabian Peninsula, and Horro birds following Orthodox Christianity down the course of the Nile. There is also selection based on appearance such as comb type that may, if anything, be detrimental to disease resistance or productivity with however the price or reduce fertility. Rose comb was a distinctive sign of indigenous, particularly in Horry, a guarantee of adaptability and taste. Indeed, we were frequently told that villagers don’t want the farenghi (foreign) chicken. In one Jarso village, we saw children wearing T-shirts recently donated by an aid charity. We were told they were also given farenghi chicken but these had all died, so the shirts where the only lasting legacy; a well-meaning intervention that had, sadly, proved unsuccessful.
That chickens are so locally adapted despite being so morphologically similar (‘Fifty Shades of Brown’) does present challenges to increasing productivity. Simple single interventions in development such as introducing modern hybrid chicken breeds have proved largely unsuccessful, as described above. Any development intervention, including breeding programmes, need to take into account the local physical, cultural and social environments. Any interventions need to have a degree of flexibility so they are able to be tailored to local needs and preferences. There is not a ‘one size fits all’ chicken for Ethiopia or any village system. It could be argued that improvements in management, the use of vaccination and improvements to disease control such as simple biosecurity measures are as important as the genetic potential of the bird. Such measures need improvements in access to information and training.
The success of the project relied on the hard work and determination of the teams of the ground, not just the authors listed, but drivers and field workers who dealt with long working hours, difficult terrain, travel and time away from family. Most importantly of all, we relied on the good will of the villagers in both regions and the development agents associated with each woreda who allowed us to sample their animals and gave their time to the study and showed us support throughout. In the closing stages of the project we revisited each village and told the farmers our main findings within the context of their village and shared simple management tips and good practices we found. We are continuing to feed back to the farmers through the development of a poultry health smartphone app for village, semi-intensive and commercial production in Ethiopia.
Sadly, our friend and co-author Pete Kaiser passed away during the later stages of data analysis. Pete was a larger-than-life character, a generous collaborator in the field of avian immunology and genomics and was very proud to have played a key role in this research. Most importantly he was a great mentor and a loyal friend. We miss him dearly.