A stud book, also called a breed registry, is a list of all of the known individual animals in a breed. Some stud books are quite old, and include bloodlines which stretch back for centuries. If an animal is registered in a stud book, it is considered to be “pure blood,” and is accompanied with registration papers which indicate this. In addition, most pureblood animals are tattooed or microchipped so that they can be readily identified throughout life. In addition, a stud book serves as a directory of available breeding animals, allowing breeders to use the stud book to make matches.
Generally, a stud book is administered by a breed club or a group which is trying to maintain the integrity of a breed. Stud books can be established for any breed of animal, but they usually encompass dogs, cats, and horses. In order to be included in a stud book, most animals must pass a physical examination to ensure that they meet the breed standard. A breed standard is a list of descriptive points which all animals within a breed possess, and it typically includes allowed colors, descriptions of body type, and other identifying points which can be used to distinguish animals from that breed. Animals which meet the breed standard are contributing to the overall history and continued well being of the breed, and can be shown in that breed class at events.
In a closed stud book, the parents of an animal being registered must both be in the stud book. In some cases, stud books are maintained by multiple organizations or nations. If one stud book has a reciprocal agreement with another stud book, it will accept animals with one or more parents from the other stud book. This helps to prevent inbreeding, by encouraging matches from different regions. Once a stud book is closed, the animals registered in it are considered to be “foundation stock,” meaning that every registered animal from then on will be a descendant of the foundation stock.
In an open stud book, any animal which meets the breed standard will be registered. The open stud book is encouraged for many breeds, as inbreeding is a serious issue with many closed stud books. Open stud books allow more genetic exchange, ensuring that specimens of the breed will be strong and healthy. Another type of stud book is a merit or performance stud book, which awards registration on the basis of conformation to the breed standards, or performance, as is the case with stud books which register working dogs.
The nomenclature in a stud book can sometimes be perplexing. Typically, an animal is given a registration name when it is included in a stud book which includes information about its predecessors or where it was bred. For example, horses with “War” in their names are descendants of Man O'War, one of the most famous equestrian athletes of all time. An animal is also given a “call name,” which is the name trainers and people who work with the animal use. A call name is often entirely unrelated to the registered name of the animal, which can lead to confusion.