Crossbreed
A crossbreed is an organism with purebred parents of two different breeds, varieties, or populations. Crossbreeding, sometimes called "designer crossbreeding", is the process of breeding such an organism. While crossbreeding is used to maintain health and viability of organisms, irresponsible crossbreeding can also produce organisms of inferior quality or dilute a purebred gene pool to the point of extinction of a given breed of organism.[1]
A domestic animal of unknown ancestry, where the breed status of only one parent or grandparent is known, may also be called a crossbreed though the term "mixed breed" is technically more accurate. Outcrossing is a type of crossbreeding used within a purebred breed to increase the genetic diversity within the breed, particularly when there is a need to avoid inbreeding.
In animal breeding, crossbreeds are crosses within a single species, while hybrids are crosses between different species. In plant breeding terminology, the term crossbreed is uncommon, and no universal term is used to distinguish hybridization or crossing within a population from those between populations, or even those between species.
Designer crossbreed
A designer crossbreed or designer breed is a crossbred animal that has purebred parents, usually registered with a breed registry, but from two different breeds. These animals are the result of a deliberate decision to create a specific crossbred animal.[2] Less often, the animal may have more than two pure breeds in its ancestry, but unlike a mutt or a mongrel, its entire pedigree is known to descend from specific known animals. While the term is best known when applied to certain dog crossbreeds, other animals such as cattle, horses, birds[3] and cats may also be bred in this fashion. Some crossbred breeders start a freestanding breed registry to record designer crossbreds, other crossbreds may be included in an "appendix" to an existing purebred registry. either form of registration may be the first step in recording and tracking pedigrees in order to develop a new breed.
The purpose of creating designer crossbreds is usually one or more of the following reasons:
- to breed animals with heterosis, commonly known as "hybrid vigor",[4]
- to create animals with more predictable characteristics than mixed breed or mongrel breeding,
- to avoid certain undesirable genetic diseasesthat plague many purebred animals,
- to develop an animal that combines what are viewed as the best traits of two or more breeds,[4]
- as the preliminary steps toward developing a new animal breed.[2]
Breeders of designer crossbreds borrow the
There are disadvantages to creating designer crossbreeds, notably the potential that the cross will be of inferior quality or that it will not produce as consistent a result as would breeding purebred animals. For example, the
Crossbreeds in specific animals
Cats
The many newly developed and recognized breeds of domestic cat are crossbreeds between existing, well-established breeds (sometimes with limited hybridization with some wild species), to either combine selected traits from the foundation stock, or propagate a rare mutation without excessive inbreeding. However, some nascent breeds such as the Aegean cat are developed entirely from a local landrace population. Most experimental cat breeds are crossbreeds.
Cattle
In cattle, there are systems of crossbreeding. In many crossbreeds, one animal is larger than the other. One is used when the purebred females are particularly adapted to a specific environment, and are crossed with purebred bulls from another environment to produce a generation having traits of both parents.[7]
Sheep
The large number of breeds of sheep, which vary greatly, creates an opportunity for crossbreeding to be used to tailor production of lambs to the goal of the individual stockman.[8]
Llamas
Results of crossbreeding classic and woolly breeds of llama are unpredictable. The resulting offspring displays physical characteristics of either parent, or a mix of characteristics from both, periodically producing a fleeced llama. The results are increasingly unpredictable when both parents are crossbreeds, with possibility of the offspring displaying characteristics of a grandparent, not obvious in either parent.[9]
Dogs
A crossbred dog is a cross between two (sometimes more) known breeds, and is usually distinguished from a
Horses
Crossbreeding in horses is often done with the intent of ultimately creating a new breed of horse. One type of modern crossbreeding in horses is used to create many of the
Hybrid animals
A hybrid animal is one with parentage of two separate species, differentiating it from crossbred animals, which have parentage of the same species. Hybrids are usually, but not always, sterile.[10]
One of the most ancient types of hybrid animal is the
At one time it was thought that dogs and wolves were separate species, and the
Mixed breeds
A mixed-breed animal is defined as having undocumented or unknown parentage, while a crossbreed generally has known, usually purebred parents of two distinct breeds or varieties. A dog of unknown parentage is often called a mixed-breed dog, "mutt" or "mongrel." A cat of unknown parentage is often referred to as a domestic short-haired or domestic long-haired cat generically, and in some dialects is often called a "moggie". A horse of unknown bloodlines is called a grade horse.
See also
- Artificial selection
- Canid hybrid
- Heterosis
- Introgression
- Selective breeding
References
- ^ "The sad truth about animal hybrids". Archived from the original on 2020-11-23. Retrieved 2019-07-19.
- ^ a b c d e "What is a Designer Dog Breed - About Hybrid Dogs". Dogs.about.com. 2013-07-14. Archived from the original on 2016-11-04. Retrieved 2013-10-04.
- ^ Stephens, Carrie (2022-11-05). "Can Parrots Crossbreed? (Hybrid Parrots)". All About Parrots. Retrieved 2022-11-15.
- ^ a b "Crossbreeding Beef Cattle - Home - Virginia Cooperative Extension". Pubs.ext.vt.edu. Retrieved 2013-10-04.
- ^ MarkHolland. "F2 generation - definition from". Biology-Online.org. Retrieved 2013-10-04.
- ^ a b ""Designer Dogs" vs 'Purebred Dogs"". IDCBA. Archived from the original on 2013-10-05. Retrieved 2013-10-04.
- ^ Cross breeding systems for beef cattle larger Archived 2008-06-08 at the Wayback Machine Department of Primary Industries and Fisheries, Queensland
- ^ Crossbreeding In Sheep, by Angie Bailey, Jason Canup and Jorge Lucena Archived 2008-05-24 at Wikiwix Purdue University, US
- ^ "classic llamas". lostcreekllamas.com. Archived from the original on 24 August 2017. Retrieved 1 May 2018.
- ^ Anitei, Stefan. "Why Are Hybrids Sterile ?". softpedia.com. Archived from the original on 1 January 2018. Retrieved 1 May 2018.
- ^ "An Ancient Livestock, by Barbara Lang". alpacasincanada.com. Archived from the original on 13 February 2012. Retrieved 1 May 2018.