Sex-links are
crossbred
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 main ...
chicken
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult m ...
s whose color at hatching is differentiated by sex, thus making
chick sexing
Chick sexing is the method of distinguishing the sex of chickens and other hatchlings, usually by a trained person called a chick sexer or chicken sexer. Chicken sexing is practiced mostly by large commercial hatcheries to separate female chick ...
an easier process. Sex-links come in several varieties. As hybrids of laying or dual-purpose breeds infused with extra vigor via
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 ...
, sex-links can be extremely good egg-layers which often produce 300 eggs a year or more depending on the quality of care and feed. The color of their eggs vary according to the mix of breeds, and blue-green eggs are possible.
Chicks of a single breed that are similarly sex-linked are called autosex chickens, a term developed to differentiate between
sex linkage
Sex linked describes the sex-specific patterns of inheritance and presentation when a gene mutation (allele) is present on a sex chromosome (allosome) rather than a non-sex chromosome (autosome). In humans, these are termed X-linked recessive, ...
in purebred chickens versus sex linkage in crossbreeds.
Sex-link types
Many common varieties are known as the black sex-link (also called black stars) and the red sex-link (also called red stars). More specific variety names are common as well.
* Black sex-link like "Black rocks" are a cross between unique specially bred hybrid strains of
Rhode Island Red
The Rhode Island Red is an American breed of domestic chicken. It is the state bird of Rhode Island. It was developed there and in Massachusetts in the late nineteenth century, by cross-breeding birds of Oriental origin such as the Malay with ...
rooster (but any non-white and non barred rooster may be used for other black sex-link crosses) and a
Barred Rock hen (which carry both extended black and barring genes).
* Red sex-links are a cross between a Rhode Island Red or New Hampshire rooster and a
White Rock (This variety pair is known as a
Golden Comet
Golden means made of, or relating to gold.
Golden may also refer to:
Places United Kingdom
*Golden, in the parish of Probus, Cornwall
* Golden Cap, Dorset
*Golden Square, Soho, London
*Golden Valley, a valley on the River Frome in Gloucestershi ...
),
Silver Laced Wyandotte, Rhode Island White, or
Delaware
Delaware ( ) is a state in the Mid-Atlantic region of the United States, bordering Maryland to its south and west; Pennsylvania to its north; and New Jersey and the Atlantic Ocean to its east. The state takes its name from the adjacent Del ...
hen.
Examples of a red-linked breeds include the
Red Shaver
The Red Shaver is a sex linked breed of chicken developed in Canada. Pullets are reddish-brown in colour with white underfeathers, while males are white with a few red markings on the feathers. They are a hardy, dual-purpose breed laying brown eg ...
and
ISA Brown
The ISA Brown is a crossbreed of chicken, with sex-linked coloration. It is thought to have been the result of a complex series of crosses including but not limited to Rhode Island Reds and Rhode Island Whites, and contains genes from a wide ...
sex-links which are found in Canada.
White birds should not be used in sex-linked crosses because white colour allele is sometimes dominant and sometimes recessive.
Sex-linked Information
/ref>
Gallery
File:A_Red_Sex_Link_Rooster_"Freckles".jpg, A red sex-link rooster
File:Black Rock Hen 'Blackie'.jpg, A Black Rock hen
File:RedStarhen.jpg, A red sex-link pullet
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult m ...
File:Beautiful Roo by sejr.jpg, A black sex-link rooster
File:Shipped pullets.jpg, Shipped pullets
File:Linda Lee, a pet Red Sex Link hen (2004).jpg, Red sex-link hen
File:Black Sex Link Chicken.JPG, Black sex-link rooster
See also
* ZW sex-determination system
The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects (including butterflies and moths), the schistosome family of flatworms, ...
* List of chicken breeds
There are hundreds of chicken breeds in existence. Domesticated for thousands of years, distinguishable breeds of chicken have been present since the combined factors of geographical isolation and selection for desired characteristics created regi ...
References
External links
{{chicken
Chicken crossbreeds