In the group formation simulation, potential new breeding groups are formed from the list of candidate animals based on the genetic value of those candidates, and within-group relationships that must be avoided. Candidates are chosen with the Source and "Include animals by" controls above: the highest-ranked N animals from the Genetic Value Analysis, every animal not labeled Low Value (the genetic-value floor), every animal in the current pedigree, or only the animals whose IDs you paste into the Animal IDs box. Only living animals are used, whatever the Source: an animal counts as alive when its Status is ALIVE (or, in a pedigree with no Status column, when it has no exit date).

Please see the Genetic Value Analysis and Breeding Group Description tab for a fuller description of this process.

The algorithm ignores between-animal kinship that is:

1. Smaller than the specified level (the default is a kinship of 0.25, which ignores everything more distant than parent-offspring or full siblings; use 0.015625 to ignore only relatedness more distant than second cousins). Pairs at or above the level are kept apart.
2. Where one of the animals is younger than the specified minimum breeding age (default is to ignore any relationship involving an animal under 1 year old). An animal exactly at the minimum age is not ignored.
3. Between two females, which is always ignored in the application.