Sussex. An English breed, Sussex chickens were at one time the most common British table bird. Speckled Sussex is the most common variety, and they stand out from other hens with their brown plumage with white speckles.nce you've decided to keep chickens, you need to choose the chicken breed or breeds you are going to raise on your small farm or homestead. Chickens come in different colors, sizes, and personalities-and with over 200 breeds, it can be hard to choose!