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A crossbreed is an organism with
purebred
Purebreds are "cultivated varieties" of an animal species achieved through the process of selective breeding. When the lineage of a purebred animal is recorded, that animal is said to be "pedigreed". Purebreds breed true-to-type which means the p ...
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
Purebreds are "cultivated varieties" of an animal species achieved through the process of selective breeding. When the lineage of a purebred animal is recorded, that animal is said to be "pedigreed". Purebreds breed true-to-type which means the p ...
gene pool to the point of
extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
of a given
breed
A breed is a specific group of domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species. In literature, there exist several slig ...
of organism.
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
Out-crossing or out-breeding is the technique of crossing between different breeds. This is the practice of introducing distantly related genetic material into a breeding line, thereby increasing genetic diversity.
Outcrossing can be a useful ...
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
Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and o ...
.
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
Purebreds are "cultivated varieties" of an animal species achieved through the process of selective breeding. When the lineage of a purebred animal is recorded, that animal is said to be "pedigreed". Purebreds breed true-to-type which means the p ...
parents, usually registered with a
breed registry
A breed registry, also known as a herdbook, studbook or register, in animal husbandry and the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breede ...
, but from two different
breed
A breed is a specific group of domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species. In literature, there exist several slig ...
s. These animals are the result of a deliberate decision to create a specific crossbred animal.
Less often, the animal may have more than two pure breeds in its ancestry, but unlike a mutt or a
mongrel
A mongrel, mutt or mixed-breed dog is a dog that does not belong to one officially recognized Dog breed, breed and including those that are the result of intentional Dog breeding, breeding. Although the term ''mixed-breed dog'' is sometime ...
, its entire
pedigree
Pedigree may refer to:
Breeding
* Pedigree chart, a document to record ancestry, used by genealogists in study of human family lines, and in selective breeding of other animals
** Pedigree, a human genealogy (ancestry chart)
** Pedigree (animal ...
is known to descend from specific known animals. While the term is best known when applied to certain
dog crossbreed
Dog crossbreeds, sometimes called designer dogs, are dogs which have been intentionally bred from two or more recognized dog breeds. They are not dogs with no purebred ancestors, but are not otherwise recognised as breeds in their own right, ...
s, other animals such as cattle, horses, birds 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
Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a hybrid offspring. An offspring is heterotic if its traits are enhanced as a result of mixing the genetic contributions of ...
, commonly known as "hybrid vigor",
# to create animals with more predictable characteristics than
mixed breed
A mixed breed is a domesticated animal descended from multiple breeds of the same species, often breeding without any human intervention, recordkeeping, or selective breeding. Examples include:
* Mixed-breed dog, a dog whose ancestry is compl ...
or
mongrel
A mongrel, mutt or mixed-breed dog is a dog that does not belong to one officially recognized Dog breed, breed and including those that are the result of intentional Dog breeding, breeding. Although the term ''mixed-breed dog'' is sometime ...
breeding,
# to avoid certain undesirable
recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
traits that lead to
genetic disease
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders ...
s that plague many purebred animals,
# to develop an animal that combines what are viewed as the best traits of two or more breeds,
# as the preliminary steps toward developing a new animal breed.
Breeders of designer crossbreds borrow the
technical language
Jargon is the specialized terminology associated with a particular field or area of activity. Jargon is normally employed in a particular communicative context and may not be well understood outside that context. The context is usually a particu ...
from
hybrid
Hybrid may refer to:
Science
* Hybrid (biology), an offspring resulting from cross-breeding
** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species
** Hybridity, the property of a hybrid plant which is a union of two dif ...
plant breeding: A first generation, 50–50 crossbred is an
F1 cross.
Subsequent generations may see a purebred animal crossed back on a crossbred, creating a 75/25 cross,
or a BC1 or F1b "
backcross
Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, to achieve offspring with a genetic identity closer to that of the parent. It is used in horticulture, animal breeding, and product ...
." The breeding of two crossbreeds of the same combination of breeds, creating a F2 cross, an animal that is still a 50–50 cross, but it is the second
filial generation
An F1 hybrid (also known as filial 1 hybrid) is the first filial generation of offspring of distinctly different parental types. F1 hybrids are used in genetics, and in selective breeding, where the term F1 crossbreed may be used. The term is somet ...
of the combination. A F2 cross bred to an F2 cross creates a F3 cross. Similarly, a F2 animal bred to an F1 animal creates a F2b backcross. F3 crosses and greater are called "multi-generational" crosses. In dog breeding, three generations of reliable documented breeding can be considered a "breed" rather than a crossbreed.
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
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is a frequent breed used in creation of designer crossbreeds, due to its non-shedding coat, but that trait does not always breed true when it is part of a designer cross.
Also, because breeders of crossbred animals may be less careful about genetic testing and weeding out undesirable traits,
certain deleterious
dominant gene
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
s may still be passed on to a crossbreed offspring. In an F2 cross, recessive genetic traits may also return if the parent animals were both carriers of an undesired trait.
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
Hybridization (or hybridisation) may refer to:
*Hybridization (biology), the process of combining different varieties of organisms to create a hybrid
*Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals
*Nu ...
with some wild species), to either combine selected traits from the
foundation stock
Foundation bloodstock or foundation stock refers to animals that are the progenitors, or foundation, of a breed or of a given bloodline within such. Many modern breeds can be traced to specific, named foundation animals, but a group of animals m ...
, or propagate a rare
mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...
without excessive
inbreeding
Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and o ...
. However, some nascent breeds such as the
Aegean cat
Aegean cats ( el, γάτα του Αιγαίου ''gáta tou Aigaíou'') are a naturally occurring landrace of domestic cat originating from the Cycladic Islands of Greece and western Turkey. It is considered a natural cat, developing without hu ...
are developed entirely from a local
landrace
A landrace is a domesticated, locally adapted, often traditional variety of a species of animal or plant that has developed over time, through adaptation to its natural and cultural environment of agriculture and pastoralism, and due to isolation ...
population. Most
experimental cat breeds
The following is a list of experimental cat breeds and crossbreeds that do not have the recognition of any major national or international cat registries, such as The International Cat Association (TICA) in the US, Europe, and Australasia; the Go ...
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.
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.
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.
Dogs
A ''crossbred'' dog is a cross between two (sometimes more) known breeds, and is usually distinguished from a ''
mixed-breed dog
A mongrel, mutt or mixed-breed dog is a dog that does not belong to one officially recognized breed and including those that are the result of intentional breeding. Although the term ''mixed-breed dog'' is sometimes preferred, many mongrel ...
'', which has ancestry from many sources, some of which may not be known. Crossbreeds are popular, due to the belief that they have
increased vigor without loss of attractiveness of the dog. Certain planned crossbreeding between purebred dogs of different breeds are now widely known as "designer dogs" and can produce puppies worth more than their purebred parents, due to a high demand.
Horses
![National Show Horse](https://upload.wikimedia.org/wikipedia/commons/0/08/National_Show_Horse.jpg)
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
warmblood
Warmbloods are a group of middle-weight horse types and breeds primarily originating in Europe and registered with organizations that are characterized by open studbook policy, studbook selection, and the aim of breeding for equestrian sport. ...
breeds. Warmbloods are a type of horse used in the
sport horse
A sport horse or sporthorse is a type of horse, rather than any particular breed. The term is usually applied to horses bred for the traditional Olympic equestrian sporting events of dressage, eventing, show jumping, and combined driving, but ...
disciplines, usually registered in an
open stud book
A breed registry, also known as a herdbook, studbook or register, in animal husbandry and the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breeders ...
by a
studbook selection Studbook selection is a process used in certain breeds of horses to select breeding stock. It allows a breed registry to direct the evolution of the breed towards the ideal by eliminating unhealthy or undesirable animals from the population. The rem ...
procedure that evaluates conformation, pedigree and, in some animals, a training or performance standard. Most warmblood breeds began as a cross of
draft horse
A draft horse (US), draught horse (UK) or dray horse (from the Old English ''dragan'' meaning "to draw or haul"; compare Dutch ''dragen'' and German ''tragen'' meaning "to carry" and Danish ''drage'' meaning "to draw" or "to fare"), less often ...
breeds on
Thoroughbred
The Thoroughbred is a horse breed best known for its use in horse racing. Although the word ''thoroughbred'' is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thoroughbred breed. Thoroughbreds are c ...
s, but have, in some cases, developed over the past century to the point where they are considered to be a true-breeding population and have a
closed stud book
A breed registry, also known as a herdbook, studbook or register, in animal husbandry and the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breeders ...
. Other types of recognized crossbreeding include that within the
American Quarter Horse
The American Quarter Horse, or Quarter Horse, is an American breed of horse that excels at sprinting short distances. Its name is derived from its ability to outrun other horse breeds in races of a quarter mile or less; some have been clocked at s ...
, which will register horses with one Thoroughbred parent and one registered Quarter Horse parent in the "Appendix" registry, and allow such animals full breed registration status as Quarter Horses if they meet a certain performance standard. Another well-known crossbred horse is the
Anglo-Arabian
The Anglo-Arabian or Anglo-Arab is a crossbred, part-Arabian horse that now also has its own status as a horse breed. It is the result of a Thoroughbred (hence, the prefix "Anglo") being crossed with an Arabian. The cross can be made betw ...
, which may be produced by a purebred
Arabian horse
The Arabian or Arab horse ( ar, الحصان العربي , DIN 31635, DMG ''ḥiṣān ʿarabī'') is a horse breed, breed of horse that originated on the Arabian Peninsula. With a distinctive head shape and high tail carriage, the Arabian is ...
crossed on a Thoroughbred, or by various crosses of Anglo-Arabians with other Anglo-Arabians, as long as the ensuing animal never has more than 75% or less than 25% of each breed represented in its pedigree.
Hybrid animals
A
hybrid
Hybrid may refer to:
Science
* Hybrid (biology), an offspring resulting from cross-breeding
** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species
** Hybridity, the property of a hybrid plant which is a union of two dif ...
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.
One of the most ancient types of hybrid animal is the
mule
The mule is a domestic equine hybrid between a donkey and a horse. It is the offspring of a male donkey (a jack) and a female horse (a mare). The horse and the donkey are different species, with different numbers of chromosomes; of the two pos ...
, a cross between a female
horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million y ...
and a male
donkey
The domestic donkey is a hoofed mammal in the family Equidae, the same family as the horse. It derives from the African wild ass, ''Equus africanus'', and may be classified either as a subspecies thereof, ''Equus africanus asinus'', or as a ...
. The
liger
The liger is a hybrid offspring of a male lion (''Panthera leo'') and a female tiger (''Panthera tigris''). The liger has parents in the same genus but of different species. The liger is distinct from the similar hybrid called the tigon, and ...
is a
hybrid
Hybrid may refer to:
Science
* Hybrid (biology), an offspring resulting from cross-breeding
** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species
** Hybridity, the property of a hybrid plant which is a union of two dif ...
cross between a male
lion
The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'' native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphi ...
and female
tiger
The tiger (''Panthera tigris'') is the largest living cat species and a member of the genus '' Panthera''. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily preys on u ...
. The
yattle
A dzo (also spelled zo, zho and dzho, bo, མཛོ་, mdzo) is a hybrid between the yak and domestic cattle. The word dzo technically refers to a male hybrid, while a female is known as a or . In Mongolian, it is called a (хайнаг). ...
is a cross between a
cow
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...
and a
yak
The domestic yak (''Bos grunniens''), also known as the Tartary ox, grunting ox or hairy cattle, is a species of long-haired domesticated cattle found throughout the Himalayan region of the Indian subcontinent, the Tibetan Plateau, Kachin Sta ...
. Other crosses include the
tigon
A tigon (), tiglon () (portmanteau of ''tiger'' and ''lion''), or tion () is the hybrid offspring of a male tiger (''Panthera tigris'') and a female lion (''Panthera leo''). (between a male tiger and female lion) and
yakalo
The yakalo is a cross of the yak (''Bos grunniens'') and the American bison (''Bison bison'', known as a buffalo in North America). It was produced by hybridisation experiments in the 1920s, when crosses were made between yak bulls and both pur ...
(between a yak and
buffalo). The Incas recognized that hybrids of ''Lama glama'' (llama) and ''Vicugna pacos'' (alpaca) resulted in a hybrid with none of the advantages of either parent.
At one time it was thought that dogs and wolves were separate species, and the
crosses between dogs and wolves were called wolf hybrids. Today wolves and dogs are both recognized as ''
Canis lupus
The wolf (''Canis lupus''; : wolves), also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, and gray wolves, as popularly un ...
'', but the old term "wolf hybrid" is still used.
Mixed breeds
A mixed-breed animal is defined as having undocumented or unknown parentage, while a crossbreed generally has known, usually
purebred
Purebreds are "cultivated varieties" of an animal species achieved through the process of selective breeding. When the lineage of a purebred animal is recorded, that animal is said to be "pedigreed". Purebreds breed true-to-type which means the p ...
parents of two distinct breeds or varieties. A dog of unknown parentage is often called a mixed-breed dog, "mutt" or "
mongrel
A mongrel, mutt or mixed-breed dog is a dog that does not belong to one officially recognized Dog breed, breed and including those that are the result of intentional Dog breeding, breeding. Although the term ''mixed-breed dog'' is sometime ...
." A cat of unknown parentage is often referred to as a
domestic short-haired
A domestic short-haired cat is a cat possessing a coat of short fur, not belonging to any particular recognised cat breed. In Britain they are sometimes colloquially called moggies. Domestic short-haired cats are distinct from the British Shortha ...
or
domestic long-haired cat
A domestic long-haired cat is a cat of mixed ancestry – thus not belonging to any particular recognised cat breed – possessing a coat of semi-long to long fur. Domestic long-haired cats should not be confused with the British Longhair, ...
generically, and in some dialects is often called a "moggie". A horse of unknown bloodlines is called a
grade horse
A grade horse is a horse whose parentage is unknown, unidentifiable, or of significantly mixed breeding. This differs from purebred animals of known bloodlines and also differs from deliberately crossbred animals that are produced with an intent o ...
.
See also
*
Artificial selection
Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant m ...
*
Canid hybrid
Canid hybrids are the result of interbreeding between the species of the genus ''Canis''. This often occurs in the wild, and in particular between domestic or feral dogs with wild native canids.
Genetic considerations
The wolf-like canids are a g ...
*
Heterosis
Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a hybrid offspring. An offspring is heterotic if its traits are enhanced as a result of mixing the genetic contributions of ...
*
Introgression
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Intr ...
*
Selective breeding
Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant mal ...
References
{{Authority control
Animal breeding
Breeding