Domestication is the process by which animals become adapted to the environment provided by humans and is defined in different ways. Price (1984) defined domestication as “that process by which a population of animals becomes adapted to man and to the captive environment by some combination of genetic changes occurring over generations and environmentally induced developmental events reoccurring during each generation”.

The process of domestication involves a number of changes in the living environment of animals such as very limited living easy availability of food and water etc. Additionally, humans have changed the selection pressure. The process of domestication and more specifically the altered selection pressure has produced a number of correlated behavioural, morphological and physiological changes among different animal species. For example, earlier sexual maturation, alteration of pigmentation and so on. Therefore, domestic phenotype refer to that trait altered during domestication, differs from their wild ancestor and seen among many domesticated breeds.

Chicken domestication believed to have started in South East Asia at ~800 years ago. Red Junglefowl (Gallus gallus) is generally considered as the common ancestor of all domesticated chicken breeds (Gallus gallus domesticus). Chicken may initially be been kept for cultural purposes such as, decoration, cock fighting or for sacrificing for religious purpose. Selective breeding of chicken for production purposes may have been started by the Romans. During domestication of chicken, selection for numerous different colour phenotypes has occurred, giving rise to a wealth of different coloured domestic breeds that differ from their wild ancestors. By utilizing the domestication process and the modern genomic techniques it is possible to map the genetic architecture of plumage colour pigmentation

The visual appearance of chickens’ plumage colour is usually associated with the amount, type and packaging of two different kinds of melanins (eumelanina and pheomelanin) and is controlled by many genes located in different chromosomes. Many genes at the typical locui that are associated with chicken plumage colour variations have already been identified. For example, SLC45A2, MC1R, PMEL17 etc. However, many remain to be identified. Therefore, this study aims to identify additional Quantitative Trait Loci (QTLs) affecting chicken’s plumage colour.