Black Sex Link

Bird

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.

http://en.wikipedia.org/wiki/Black_Sex_Link