I am often asked why silkies that are hatched out from breeders look so different from silkies that come from large hatcheries. The short answer is that serious silkie breeders take care to improve their silkies by breeding to fix good traits and eliminating bad ones as they set up their breeding pens.
In nature, jungle fowl used natural selection when choosing their mates. Males that were strong and vigorous had a large following of female hens. These strong genes were passed along to their descendants. Weaker males were not selected as worthy mates by the females.
After domestication occurred, the farmer used artificial selection to improve his flock. Single mating is taking one outstanding female and one outstanding male and breeding them. Their offspring should be perfect. Right? Not always. There is no such thing as a perfect bird. Other methods are needed.
First, the breeder needs a plan. They need to have specific goals. Is there something that needs to be improved? Those would be things like, type, feather color, skin color or feather quality. Maybe your breeding goal is to get rid of something such as extra claws or toenails.
Most breeders start with a good set of birds that are excellent examples to begin with. They can breed with those birds for many years provided they keep the best and sell or cull the rest. The best must also be the most vigorous and healthy. By constantly improving your flock by keeping the best and the most vigorous and only breeding with those, you can continue to breed for many years without going outside of your own flock.
Line breeding is one way to keep up the health of your flock but still keep it closed to other birds. Introducing new birds and breeding with them can bring recessive gene traits to the fore front and you can be bringing in unwanted traits that will be difficult to later breed out.
Line breeding involves pairing fathers with daughters and sons with mothers. Take it a step further and breed Grandfathers with granddaughters and grandmothers with grandsons. You do not want to breed brother to sister if you can help it as that is a very close shared gene pool. Excessive inbreeding can cause infertility, severe deformities, and lethal genes but it can also produce some spectacular birds.
Every seven years or so, you can then out cross to bring in some fresh blood lines. It is best to go back to your original breeder to get these out cross birds. They will have the same line or strain as you do and you will encounter less surprises in your offspring.
Line breeding and Spiral breeding are two methods for continuing to breed healthy birds without resorting to too much out crossing of new blood. With silkies it is important to keep your colors separated, especially if you are breeding with thoughts of showing in a poultry show later.
Most people do backyard breeding for fun and get all kinds of interesting combinations, but if you are serious about wanting to improve the breed, then work hard at striving to meet the Standard of Perfection. These standards can be found online for every breed of chicken and are very worthwhile reading. Good luck in your breeding endeavors.