Blue "Croad Langshans" were created by crossing Langshans with
The colour called 'blue' is really a bluish slate grey.
It is produced by an incompletely dominant autosomal gene Bl / bl which causes the black eumelanin granules in the feathers to be more sparsely distributed than in the case of black; also they are oval rather than rod-shaped.
If two blue genes Bl / Bl are present, the effect of this dilution is doubled to splash (white with a few dark spots).
The homozygous bl / bl is normally black .
The blue feathered birds are heterozygous Bl / bl, and so do not breed true.
Crossing two blues, both Bl / bl will produce 25% black (bl /bl), 50% blue (Bl / bl) and 25% splashed white (Bl /Bl).
Blue "Croad Langshans" are magnificent birds, benefitting no doubt from the hybrid vigour obtained by crossing different breeds. They are also a good example of how easy it is to cross rare breeds out of existence.
In England, home of the Croads, black and white are the only recognised colours.
Article in "Poultry", March 27, 1937 page 295
transcribed text below, for original article in .pdf click title:
By E.J. Winton, Windsor, N.S.W.
My blue Langshans were produced by crossing a blue Andalusian hen with Langshan male, the progeny being mated back to pure Langshans. After several years all the Andalusian characters (such as large comb, white earlobes, clean legs, white eggs, etc.) were eliminated, with the exception of the blue color. The blues now breed true to type and are bred to the Chinese Langshan standard and they have frequently secured first prize when shown among the blacks as Chinese Langshans.
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