A breed is a specific group of domestic animals having
homogeneous
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, siz ...
appearance (
phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological prop ...
), homogeneous
behavior
Behavior (American English) or behaviour ( British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as w ...
, and/or other characteristics that distinguish it from other organisms of the same
species
In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...
. In literature, there exist several slightly deviating definitions. Breeds are formed through
genetic isolation
Introduction
Geographic isolation or other factors that prevent reproduction have resulted in a population of organisms with a change in genetic diversity and ultimately leads to the genetic isolation of species. Genetic isolates form new specie ...
and either natural
adaptation to the environment or
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 ma ...
, or a combination of the two. Despite the centrality of the idea of "breeds" to animal husbandry and agriculture, no single, scientifically accepted definition of the term exists. A breed is therefore not an objective or biologically verifiable classification but is instead a
term of art
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 partic ...
amongst groups of breeders who share a consensus around what qualities make some members of a given species members of a nameable subset.
Another point of view is that a breed is consistent enough in type to be logically grouped together and when mated within the group produce the same type. When bred together, individuals of the same breed pass on these predictable traits to their offspring, and this abilityknown as "
breeding true"is a requirement for a breed.
Plant
Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...
breeds are more commonly known as
cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
s. The offspring produced as a result of breeding animals of one breed with other animals of another breed are known as
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 mai ...
s or mixed breeds. Crosses between animal or plant variants above the level of breed/cultivar (i.e. between species,
subspecies,
botanical ''variety'', even different
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial ...
) are referred to as ''
hybrids''.
[Banga, Surinder S. (November 25, 1998). ''Hybrid Cultivar Development'', p. 119. Springer-Verlag. ]
Breeding: selection by breeders
The
breeder
A breeder is a person who selectively breeds carefully selected mates, normally of the same breed to sexually reproduce offspring with specific, consistently replicable qualities and characteristics. This might be as a farmer, agriculturalist ...
(or group of breeders) who initially establishes a breed does so by
selecting individual animals from within a
gene pool
The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species.
Description
A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can surv ...
that they see as having the necessary qualities needed to enhance the breed model they are aiming for. These animals are referred to as
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 ...
. Furthermore, the breeder mates the most desirable representatives of the breed from his or her point of view, aiming to pass such characteristics to their
progeny. This process is known as
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 ma ...
. A written description of desirable and undesirable breed representatives is referred to as a
breed standard
In animal husbandry or animal fancy, a breed standard is a description of the characteristics of a hypothetical or ideal example of a breed. The description may include physical or morphological detail, genetic criteria, or criteria of athlet ...
.
Breed characteristics
Breed specific characteristics, also known as breed traits, are inherited, and
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 th ...
animals pass such traits from
generation
A generation refers to all of the people born and living at about the same time, regarded collectively. It can also be described as, "the average period, generally considered to be about 20–30 years, during which children are born and gro ...
to generation. Thus, all specimens of the same breed carry several genetic characteristics of the original foundation animal(s). In order to maintain the breed, a breeder would select those animals with the most desirable traits to achieve further maintenance and developing of such traits. At the same time, the breed would avoid animals carrying characteristics undesirable or not typical for the breed, including faults or
genetic defects. The
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using ...
within the same breed should consist of a sufficient number of animals to maintain the breed within the specified parameters without the necessity of forced
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 an ...
.
Domestic animal breeds commonly differ from country to country, and from nation to nation. Breeds originating in a certain country are known as "native breeds" of that country.
Lists of breeds
See also
*
Cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
*
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 isolati ...
*
Plant variety (disambiguation) Plant variety may refer to:
*Variety (botany), a formal rank, in taxonomic nomenclature, below subspecies
*Colloquially (and historically):
**Cultivar, especially of grapes and rice
**Hybrid (biology), more generally
**Any form (botany) (a taxonomic ...
*
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 th ...
*
Race (biology)
In biological taxonomy, race is an informal rank in the taxonomic hierarchy for which various definitions exist. Sometimes it is used to denote a level below that of subspecies, while at other times it is used as a synonym for subspecies. It h ...
*
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 ma ...
*
Subspecies
*
Strain (biology)
In biology, a strain is a genetic variant, a subtype or a culture within a biological species. Strains are often seen as inherently artificial concepts, characterized by a specific intent for genetic isolation. This is most easily observed in mic ...
*
Animal Genetic Resources for Food and Agriculture
References
Further reading
FAO. 2007. The Global Plan of Action for Animal Genetic Resources and the Interlaken Declaration. Rome.*
ttp://www.fao.org/publications/sowangr/en/ FAO. 2015. The Second Report on the State of the World's Animal Genetic Resources for Food and Agriculture. Rome.
External links
Commission on Genetic Resources for Food and Agriculture-
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
of the
United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmonizi ...
*
Domestic Animal Diversity Information System*
*
ttp://www.ansi.okstate.edu/breeds/ Breeds of Livestock - Oklahoma State University
{{Authority control
Domesticated animals
Zoological nomenclature