Please bless me with knowledge about blue chickens my beloved if you have any
There is 3 different genes that dilute black to "blue" i will talk about two of them
Blue (BL) is a dominant gene that is different in its heterozygous and homozygous form. Birds who are heterozygous for blue are what is known as "Blue" while birds that are homozygous are known as "Splash"
Blue can be difficult to work with since breeding two blue birds together can produce Splash birds which can be tricky if your breed standard doesnt allow homozygous blue birds. Blue also ranges from a very dark grey to a very light almost white grey with many shades inbetween depending on other genes and the base color at play. This means that Blue doesnt always breed true.
Here is a Blue (heterozygous) australorp next to a typical black one
and here is a Blue next to a Splash (homozygous)
Splash and Blue birds periodically have to be crossed back to black birds to retain color. Birds who are not eventually crossed back can fade to basically white which is why alot of breeders try to avoid having only splash and blue birds. What some breeders do is that they will also have a blue and a black pen where they raise high quality birds so whenever the blues need more blacks the breeder already has some good birds to choose from.
When two blue (BL) chickens are bred they will produce around
50% Blue (heterozygous birds)
25% black (no blue gene)
25% Splash (homozygous birds)
When you breed a Splash to a black bird you get
100% Blue
When you breed a Splash to Splash to get
100% Splash
You can see that splash birds can still have their place in the breeding pen (with crossing to black birds) since they can produce you more blues, the individuals might not be popular at some shows but hobby keepers love them so they always have a place.
Second gene that dilutes black to blue is one of my favorite genes and that is Lavender (lav) which is also known as Self Blue which is an autosomal recessive which only expresses in its homozygous form.
Lavender is the only gene that dilutes both black and red pigments and its works by preventing the black and red pigments from entering the feather rather then altering the pigment itself (like blue does)
Since lavender breeds true,meaning if your breed two lavender together they will produce more lavenders, you can create very delicate blue and gold shades with lavender so its very popular to use in color projects.
lavender isnt without its own trickiness though. The dreaded "feather shredder" or "tail shredder gene" is thought to be closely linked to lavender. Lavender doesnt cause tail shredder but it is thought that the gene tethers to lavender very easily likely due to the fact that pigment helps strengthen feathers and lavender birds are deficient in pigment
This is what tail shredder looks like. It can happen to any bird(this is a black sumatra), even one that doesnt carry lavender but its important if you breed lavender birds to always breed birds with good feather quality. Crossing a lavender bird back to a black bird just hides the problem, birds with the shredder gene shouldnt be used for breeding as this gene can easily ruin lines if introduced.
