Put simply, an open pedigree is one in which any given dog appears only once. A pedigree is basically the dog's family tree. In a hypothetical open pedigree, there are literally billions of genes involved and the results of such breedings are unpredictable, to say the least. You are basically dealing with a deck full of wild cards. Line breeding reduces the number of ancestors in a pedigree, which can help a knowledgeable breeder set desirable traits. This is one of the areas where having a mentor is important. Haphazard line breeding may result in doubling up on undesirable traits and genetic faults. A good working knowledge of genetics is vital in setting desirable traits, whether dominant or recessive, and in avoiding undesirable and sometimes lethal traits.
This is a simplified explanation but it does give you an idea that just putting two dogs together is not the way to start a breeding program. Open pedigrees will reduce the incidence of recessive traits being expressed, but remember that not all recessive traits are undesirable. The books I recommended earlier, along with a knowledgeable mentor, will help you along. |