Quantitative Trait Loci (QTLs) are chromosomal regions containing genes causing variation in continuous traits. Two alleles are Identical-By-Descent (IBD) if they are copies of the same original allele. For each point on a chromosome, it is possible to predict IBD probabilities among individuals given a pedigree and marker information and use them to map QTLs in farmed species. Pedigree founders can either be assumed unrelated (George et al. 2000) or related through distant common ancestors (Meuwissen and Goddard 2000). The relationship among founders was estimated through simulating the history of a model population. Linking the current population with original ancestors, without a pedigree, is central to the theory of long-term genetic contributions (Bijma 2000). Hence, in the light of this theory, it should be possible to deterministically predict IBD relationships among pedigree founders. A first step towards this objective was predicting inbreeding (F) within each animal at a chromosomal location.