Roots To Branches
LINEBREEDING, the most conservative form of inbreeding, usually results in slower improvement and more limited risk of producing undesirable offspring. It involves matings between closely or more distantly related parents, but it does not emphasize continuous sire-daughter, dam-son, or brother-sister matings.
The main purpose of linebreeding is to attempt to transmit a large percentage of one outstanding ancestor's genes to the future generations without the hazards associated with inbreeding. However, when a sire makes a name for itself the resultant linebreeding on his lines may have a profound impact upon the diversity of the breed- for good or bad.
Because linebreeding is not based strictly on mating individuals with very similar gene types, it does not cause as a rapid increase in loss of diversity. Since it will not expose undesirable recessives as extensively as closebreeding, linebreeding is generally a safer inbreeding program for most breeders to follow. However, although conservative, it does not mean linebreeding is foolproof and does not require culling. Many top "show" animals may have had cosmetic surgery to enhance their chances in the conformation ring- research and be aware of other siblings and offspring of your intended sire!
Intensive linebreeding (and resulting lack of diversity) is often directly related to an increase in the expression of many undesirable traits. Therefore, breeders using this method should carefully study pedigrees for each prospective mating. Determining if, and how closely, the ancestors are related. By following certain guidelines, the breeder can limit inbreeding within their group, while at the same time, increasing the traits of a common exceptional ancestor upon the entire strain or family.
The family tree below quickly shows the related ancestors - while this fact is slightly more hidden in the pedigree of this hypothetical animal, below.
