The main feature of breeding pets is the presence of a huge variety of their qualities. Breeders use them to breed different breeds. Thanks to the work of researchers, such breeds of pets have been bred for several centuries that it is impossible to recognize the original animal in them. As an example: Berkshire and Yorkshire pig breeds, English heavy truck and steed, Southdown and Leicester sheep, short-horned cow. Breeders were able to give some species the desired heredity.