This percentage tells you how much shared family is found on both sides of a ram's recorded pedigree.
01 · The short answer
More repeated family means a higher number
If the same ancestor shows up through both the sire and dam, the inbreeding coefficient goes up. A closer or more frequently repeated ancestor has a bigger effect than one far back in the pedigree.
It is an estimate across the pedigree. It does not mean that exactly 6.25% of every gene is a problem.
02 · How we calculate it
We trace both sides of the pedigree
SireGuide uses the standard pedigree-based inbreeding calculation. The math accounts for repeated ancestors and every known path back to them.
- Start with the sire and dam.We follow every parent that is recorded.
- Find ancestors shared by both sides.Closer and repeated matches count more.
- Calculate the percentage.When an approved pedigree changes, affected percentages are recalculated.
03 · Pedigree completeness
Missing names leave part of the story unknown
The calculation can only use the pedigree we have. If an ancestor is missing, the system cannot assume that animal was related or unrelated. That is why every percentage is shown with a pedigree-completeness score.
No shared ancestors were found in the complete recorded pedigree.
No shared ancestors were found in the known portion. The number could change when missing ancestors are added.
04 · Using the number
Use it as one piece of the breeding decision
The coefficient helps compare shared ancestry. It does not grade a ram, predict whether a mating will work, or replace genetic tests and good judgment. Read it together with pedigree completeness, bloodwork, phenotype, and your breeding goals.
See the number beside a pedigree →