A few notable examples include the Arabian Bask, the French jumper Galoubet, and the Morgan's foundation sire Justin Morgan. In the Thoroughbred, the Dosage theory is based on a list of prepotent sires. A point system predicts the racing ability of a mating. Breeders debate the success of line breeding vs. breeding type to type. No one knows for sure the results of crossing one horse with another, but analyzing the ancestors can help you make more practical predictions.
Most individuals are healthier when they have a limited number of homozygous genes.
The heterozygous genes tend to have more heartiness, more vigor, and are more reproductively sound. In analyzing a pedigree, realize that some lines carry negative traits, such as gene-linked diseases. Ewart noted that you might be able to track this inheritance by examining the sire and dam. However, a recent theory of the X-factor breeding a larger heart currently has no scientific evidence. However, one horse resulting from a mating might excel, while his or her siblings might be average in their conformation and performance.