Characterisation and monitoring of poultry genetic resources

Poultry genetic resources encompass all types of populations, from village chickens to commercial and experimental lines. Characterisation includes collection of data on population size and structure, geographical distribution, production systems in which the breed is found, phenotypic attributes (physical features, performance levels and any unique features), historical development of the breed (crossbreeding, selection). Such data can be available for standardised breeds and experimental lines, but are generally confidential for commercial lines and difficult to record for village chickens. In the past, random sample tests provided recurrent data for layer and broiler strains, but these have been discontinued. Available literature on local populations provides information on specific features such as morphological diversity, scavenging behaviour, product quality and disease resistance. Molecular markers provide useful information on genetic variability, either within or between populations, and make it possible to quantify relatedness between populations and to detect introgressions. Molecular markers contribute to define breed identity and may be used to assign individuals to their population of origin. Current results provide a reasonably complete picture of genomic variability and population structure in the domestic chicken. Yet, this does not make it possible to predict performance: phenotypic data are still needed to document molecular data. In the future, the progress of genomics may merge functional data with historical data.