Purely based on these phenotypes, one can make breeder selection decisions in several ways. The traditional process used for centuries has molded and shaped ancestral dogs into today’s modern breeds. As practiced today, this process involves measuring the important aspects of health, behavior, and performance on each young dog and its relatives, including littermates, full- or half-sibs, parents, grandparents, and even more distant ancestors, when possible. With this information in hand, phenotype selection requires the breeder to somehow put ALL these measurements into context to decide among alternative young dogs exactly which ones will be kept for breeding.
Selection using EBVs is a more advanced selection method. It uses the same phenotype measurements described above for aspects of health, behavior, and performance, but it then combines those measurements in a second step that includes pedigree relationships. The numeric value produced by this second step estimates each dog’s relative genetic worth as a breeder for a particular trait or characteristic. These estimates are known as estimated breeding values (EBVs), and they are the most accurate way known to describe the genetic potential of each young dog as a possible breeder. Key to producing accurate EBVs is to begin the process with accurately recorded pedigree relationships and accurately measured phenotypes on most dogs in a population.
