Understanding the color bulik
The Barring Gene The Barring Gene, or Barred Gene (B), and the diluted Barring Gene (Bsd) are color pigment inhibitors that cause barring as a result of inhibiting the natural color in a barred pattern. The barring or spotting that you see in a Dom is the result of white or light colored barred segments that are produced by inhibiting the natural color in that segment. The darker colors in the Dom are the non-barred genetic pigmentation of the bird---so, if you want red spots there must be red pigmentation in the bloodline, and if you want black spots there must be black pigmentation. Likewise for yellow or gold color. The Barring Gene is considered to be a variant or mutation, and was first identified by researchers in 1908. The Barring Gene initiates the barring process but the actual factors causing pigment inhibition involve a number of linked genes, and this is why there is variation in the intensity of barring, or dilution of barring. The Barring Gene is located on the sex chromosome, therefore barring is a sex-linked characteristic. The Barring Gene also inhibits tissue pigmentation, making it difficult to produce Doms with dark shanks. The Barring Gene is genetically dominant. (Bsd) is dominant over (B), and both are dominant over non-barred gene (b+).
The (B) gene expresses white barring and the (Bsd) expresses dove color or fawn color barring in females. A homozygous male (Bsd/Bsd) will be predominantly recessive white in color.
Barring is subject to dilution or dosage effects, causing male gene pairs (B/B), (B/b+), (B/Bsd), (Bsd/Bsd) and (Bsd/b+) to all show different intensities of barring. Most gamefowl have diluted barring. For example, for a Dom cock with genes (Bsd/b+), the (Bsd) gene will be dominant but the (b+) non-barred gene will have a dilution effect even though it is recessive.
Note: Remember genes are present on the male bird's sex-chromosome in pairs, but genes on the female bird's sex-chromosome are single.
The barred gene pairs in male Doms will be as stated above, but because the female Dom only has the single barred gene, she will always be either (B/-) or (Bsd/-), where (-) is the notation for the female blank gene. If a Dom also has the slow-feathering gene, the barring will be more sharply defined. The slow-feathering gene effects how rapidly the chick begins growing the first feathers. A sharply defined barring may indicate the presence of the slow-feathering gene and may not indicate purity of the barring gene. Those of you that incubate and keep chicks in a brooder can observe and compare the chick feathering.
The Bottom Line: The Dom barring can be expressed in a number of different ways with various aspects of dilution. With respect to barring, cocks are genetically complex, but the hen is genetically simple. For the hen, WHAT YOU SEE IS WHAT YOU HAVE..no hidden secrets. The barred Dom hen, no matter what bloodlines are in her ancestry, no matter what male she is bred to, will always produce 100% barred sons, subject to dilution effects.