Sex-link
Sex-links are crossbred chickens whose color at hatching is differentiated by sex, thus making chick sexing an easier process. Sex-links come in several varieties. As hybrids of laying or dual-purpose breeds infused with extra vigor via heterosis, 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 in purebred chickens versus sex linkage in crossbreeds.
Sex-link types
Many common varieties are known as the black sex-link and the red sex-link. 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 rooster and a Barred Rock hen.
- Red sex-links are a cross between a Rhode Island Red or New Hampshire rooster and a White Rock, Silver Laced Wyandotte, Rhode Island White, or Delaware hen.
White birds should not be used in sex-linked crosses because white colour allele is sometimes dominant and sometimes recessive.