Buff
The color buff is one of the least understood variaties that make up the vast array of chicken colors. None of the papers the author has read explain how the color is produced. In order to obtain the buff color, the chicken must: 1) have a gene or genes that add red pigment to the chickens plumage, 2) the chicken must carry a gene or genes that dilute the red pigment to a buff color, 3) the chicken must also carry restrictors that remove black pigment from the body of the bird, even the black in the tail of the bird. If one can breed genes into a bird that will do the above tasks, they will produce a buff bird.
There have been two studies that have genetically analyzed the color buff. One of these studies is the study by Brumbaugh and Hollander (1966) and the other by Carefoot (1995). In the study by Brumbaugh and Hollander, the genetic makeup of the Buff Minorca and the Buff leghorn were analyzed. The Buff Minorca carried the following genes: recessive wheaten (ey), sex linked gold (s+), champagne blond (Cb), mahogany (Mh), columbian (Co) and dilute (Di). The Buff leghorn was determined to have the E locus gene recessive wheaten. In the study by Carefoot, he determined that the bantam Buff Rock contains the following genes: columbian (Co), dark brown (Db), sex linked gold (s+), and dominant white (I). The author was not able to read the paper by Carefoot but did read the abstract.
The sex linked gold gene will add red pigment to the chicken. The mahogany gene will make the red even darker but it is evident in the plumage that the mahogany gene does not cause the plumage to be red. Buff birds have a diluted orange/red color. The columbian gene and the dark brown gene both add an orange hue to the red pigment.
The next obstacle would be to dilute the orange/red to a buff color. Dilution of the orange/red could be accomplished with the champagne blond and the dilute genes, in the Minorca, or the dominant white gene in the Rock.
The next step would be to add genes that would remove all of the black pigment from both the male and female birds This would allow the entire bird to be a buff color. The columbian gene, the dark brown gene and the mahogany gene are all called restrictors. These genes are able to remove black from much of the bird but none of them alone can remove all of the black. Dominant white can be an answer to this problem. Dominant white in the Rock will remove the black and allow the red to enter the tail and wings. Dominant white was not found in the Buff Minorca. So, what is removing all of the black from the wings and tail of the Buff Minorca? More research needs to be carried out to answer this question. It is the authors opinion that the restrictors as a whole work together to remove the black from the wings and tail.
Brumbaugh JA, Hollander WF, 1966. Genetics of buff and related color patterns in the fowl. Poultry Science. 45:451-457
W. C. Carefoot., 1995 Evidence that the eumelanin restrictor genes (Co) and (Db) are present in the genome of the Buff Rock bantam British Poultry Science, Volume 36, Issue 2 May , pages 205 - 207
Tim