Sex-links are cross-bred chickens whose color at hatching is differentiated by sex, thus making chick sexing an easier process. Sex-links come in many varieties, few of which are a true breed. 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.
Two common varieties are the Black sex-link (also called Black Stars) and the Red sex-link (also called Red Stars). Blacks are a cross between a Rhode Island Red or New Hampshire 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. One example of a red linked breed is the Red Shaver. In Europe, the Cream Legbar (an actual true-breeding pure breed) and ISA Brown sex-links also exist.