Lunar Boxers

INBREEDING/LINEBREEDING CO-EFFICIENT
Layman's Explanation

Inbreeding is commonly regarded as the mating of related individuals; especially closely related individuals, such as, brother/sister, father/daughter, mother/son. Half brother/sister, single and double first cousins matings are less close but still constitute inbreeding. The principle is that the mated individuals share one or more common ancestors.

Avoiding a degree of inbreeding is impossible as a little calculation will reveal. The number of ancestors doubles per generation, 2 in the first generation, 4 at the next and so on. By the time you get to 15 generations the number of ancestors exceeds 32,000. The numbers increase rapidly as you go back further and eventually exceed the number of dogs bred in any generation. Many of these distant ancestors will occur multiple times which constitutes a level of background inbreeding.

The total amount of inbreeding in the known pedigree can be calculated and is expressed as the inbreeding or linebreeding coefficient. Each parent contributes 50%, each grandparent 25%, each great grandparent 12.5%, great-great grandparent is 6.25% and great-great-great grandparents 3.25%. Looking at the five generation pedigree and adding the percentages of dogs who appear more than once gives you the co-efficient.

The significance of inbreeding is that the higher the level of inbreeding the greater the probability that the individual will inherit the same gene (good or bad!) from both sire and dam because both sire and dam trace back to a common ancestor.

Web Page Design by TDF Designs.