To the casual observer, the Plymouth barred rock and the Dominique chickens appear almost identical. Look closely, though, and you will see subtle differences. The two breeds share a heritage, so it's not just coincidence that they look so similar. The barred rock is far more common than the Dominique, which is now a relatively rare breed.
The Dominique was one of the earliest American chicken breeds, appearing in single and rose comb varieties. In the late 19th century, standardization of the breed decreed that only the rose comb -- a low comb with round nubs -- was acceptable, so the single-comb birds were used to create the Plymouth barred rock. By the 1970s, only four flocks of Dominiques were still in existence, but breed enthusiasts were able to increase the numbers. It is still a threatened breed.
Differences in Appearance
The quickest way to tell whether a bird is a barred rock or a Dominique is to look at the comb. The barred rock has a single comb, while the Dominique sports a rose comb. The head of the barred rock is more coarse than that of the refined Dominique. The Dominique has a longer tail, with greater feathering than that of the barred rock. The barred rock carries his tail lower than does the Dominique.
Poor quality specimens of either breed have similar barred feathering, but well-bred chickens have distinctly different patterns. The barred rock's feather patterns consists of black and white barring. A Dominique's feathering should have light gray bars and darker gray -- not black -- bars, with the lighter bars two times as wide as the dark ones. Each feather tip ends in bar. Bar size also varies between male and female, with roosters boasting light bars twice the size of hens. The result is a Dominique rooster considerably lighter in shade than a hen.
Eggs and Production
Both breeds lay brown eggs, with the Dominique laying an average of 180 to 260 medium-sized eggs annually. The barred rock lays a larger egg, averaging between 200 to 280 eggs annually. While the Dominique is considered primarily an egg-laying breed, the barred rock is a dual-purpose bird, raised for eggs and meat.
Both breeds have good temperaments and are docile birds. Both also do well in cold weather, with the Dominique's rose comb less vulnerable to frostbite than the single comb of the barred rock.