A few folks have emailed me to ask about the potential results of using a blue Ameraucana in a self blue (formerly known as lavender) Ameraucana pen. I wanted to take a moment to discuss the two color varieties and what results one may encounter when crossing a blue Ameraucana with a self blue Ameraucana. This is merely an educational post and is not meant to discourage anyone from pursing projects that they may enjoy. However, when asked about the subject I discourage folks from using a blue Ameraucana in a self blue Ameraucana pen as the offspring produced do not adhere to the standard. Let’s explore the differences in the blue gene (Bl) and the lavender gene (lav).
The blue gene (Bl) is a diluting gene. It is known as an autosomal incomplete dominant gene. Chickens have 39 pairs of chromosomes. They have two categories of chromosomes known as sex chromosomes and autosomes. An autosome is simply defined as a chromosome that is not a sex chromosome. Genes are contained within these chromosomes. Each parent contributes one allele to form a particular gene in a diploid organism. Incomplete dominance means that one allele is not completely expressed (or dominant) over the allele that it is paired with. This results in a phenotype that is a combination of both alleles. This explains why blue chicks produced in a blue, black and splash breeding pen are not all the exact same shade of blue. Some may be lighter in color and others may be darker in color due to the incomplete dominance.
In its heterozygous form (one copy of the Bl gene, known as Bl/bl+), black feathers are diluted to create blue plumage. In its homozygous form (two copies of the Bl gene, known as Bl/Bl), black feathers are diluted to create splash plumage. The genotype for the wild type (the non-mutated version which is black) is bl+/bl+.
The American Poultry Association standard of perfection calls for the plumage of a blue Ameraucana to be an “even shade of clear bluish slate with each feather distinctly laced with black.” While there are a few conflicting studies out there, multiple scientific studies have found that there are three genes involved in creating the black single lacing on a blue Ameraucana. Those three genes are the Pattern gene (Pg), Melanotic gene (MI) and Columbian gene (Co).
The Pattern gene is responsible for creating patterns on plumage. It organizes black pigment concentrically. The Melanotic gene is a black intensifier. It enhances and moves black pigment to the outer border of the feather. This makes the outer border black and double lacing is created (Pg+Ml). By adding Columbian (Co), which is an eumelanin restrictor, the inner laces are taken away and single lacing is created (Pg+Ml+Co).
Blue cockerels are also darker in the hackle, saddle and wingbows as a result of their sexually dimorphic plumage. I spoke with one of my mentors who has written several poultry genetics books about what creates the darker hackle, saddle and wingbows on blue cockerels and he confirmed that it is the result of additional melanizers. He stated there are around two dozen melanizers in poultry, many of which are unnamed. When blues are used in a self blue breeding pen, the cockerels have darker hackle, saddle, and wingbows. This does not adhere to the standard which calls for “no contrast in color between any of the sections.”
The lavender gene (lav) is an autosomal recessive gene. It dilutes eumelanin and pheomelanin. The lavender gene has not been shown to be epistatic to other diluters and contributes in further dilution of plumage color. Therefore, when a self blue Ameraucana that is carrying the blue gene is crossed with a self blue Ameraucana, a more diluted plumage color is created as a result of the two diluting genes. This very diluted plumage color does not adhere to the standard as the standard calls for the plumage of a self blue Ameraucana to be “a MEDIUM shade of clear blue).” Furthermore, if you mate a self blue bird carrying the blue gene with another self blue bird that is carrying the blue gene, an even further diluted plumage color can be produced with splash spots present. Curiously, you may also notice that many of the birds in these crosses have dark feather shafts as well and the standard states that self blues should be “free from shaftiness (see the attached example photo).”
In closing, three reasons to be cautious about using a blue Ameraucana in a self blue Ameraucana pen are:
1) The combination of the two diluting genes (lav and Bl) results in a very diluted plumage color that does not adhere to the standard description. The standard calls for the plumage of a self blue Ameraucana to be a “medium shade of clear blue.”
2) The Pg, MI and Co genes that a blue Ameraucana has can result in partial or incomplete lacing in offspring. This does not adhere to the standard description. The standard states that the plumage should be “free from lacing, shaftiness, mealiness and messiness.”
3) Melanizers that the blue Ameraucanas carry result in sexually dimorphic plumage on cockerels (darker hackles, saddles and wingbows) which does not adhere to the standard description. The standard states that there should be “no contrast in color between any of the sections.”
Do you have a breeding or genetic question related to Ameraucanas? Email me at firstname.lastname@example.org and I may create an educational post about it!
Are you interested in working with Ameraucanas and breeding them towards the standard? Join the Ameraucana Breeders Club at www.ameraucanabreedersclub.org!
To breed Ameraucanas to standard and to be aware of all defects and disqualifications, you will need a copy of the APA SOP book. To buy an American Poultry Association Standard of Perfection book, visit the following link:
*This post is under copyright and cannot be used or published without the consent of the author.
Poultry Science Volume 70, Issue 1, 1 January 1991, Pages 1-5.
W. C. Carefoot (1992) Inheritance of the lace‐tailed laced plumage pattern of the sebright bantam, British Poultry Science, 33:2, 297-302, DOI: 10.1080/00071669208417468
W. C. Carefoot (1988) Inheritance of the laced plumage pattern of the blue Andalusian bantam, British Poultry Science, 29:1, 175-178, DOI: 10.1080/00071668808417040
W. C. Carefoot (1986) Laced and double‐laced plumage pattern phenotypes of the domestic fowl, British Poultry Science, 27:1, 93-96, DOI: 10.1080/00071668608416858