Be careful with the term pure breed of game fowl when buying a chicken because for me there is no such as pure breed today. When you say pure meaning no other genes of other blood line in that breed, for example when you say a pure breed of sweater, means it is a one hundred percent of the genes of a sweater game fowl. The game fowl no matter what is the blood line is compose of two pairs of genes. A we can only say that is pure when both of the genes are the same but today believe me there is no such a pure breed because chicken of today are offspring of a two or more breed of blood line.
When a breeder tell you that his breed is pure don’t believe on him because again there is no such thing as pure breed today because as time pass by chicken are Pass through the next generation and it is difficult and impossible to maintain the purity of a game fowl even if the breeders will do line-breeding method the pure breed cannot be achieve. Others do back-crossing but still it is not a pure breed because when we define a pure it contains only that genes and no other even a single amount.
To have a breed of game fowl that is near to a pure breeders use the line-breeding or in-breeding like mating the sister and brother and back-crossing like mating back the daughter to father or breeding back the son to mother. Those are the ways were game fowl breeder preserve the blood line of their game fowl but again there is no such thing as a pure breed.
To those who plan to buy a pure breed of game fowl to be used as breeding material always look for a trusted breeder who are honest and have good and quality breeding materials and do not become ignorant about pure breed or purity of the breeding material that they are selling.