When we got some chicks about a year ago one of them was grey and my daughter fell in love with it. I later discovered this colour was called lavender, and had a bit of a giggle – I thought it was a slick piece of marketing to put a pretty name on a fairly dingy colour.
But now that I have lived with it for a while and seen other examples, I’m a convert. It’s not just a dingy grey, it’s quite a luminous pewter. I think it looks particularly nice on fluffy chickens such as pekins.
Lavender is a lovely gene to play with because it is a simple monogenic system. Even better, it works on top of the standard colour system rather than as part of it, so you only have a single gene to worry about. Lavender is an autosomal recessive, which means it affects both sexes and you need a copy from each parent for it to show. Birds with only one copy are carriers, they can pass it to their offspring but don’t show any evidence of it.
Lavender acts to dilute the bird’s colouring, turning black into grey and gold into blonde. White stays the same. This means you can have all your standard colours or lacing and add a lavender gene on top. The problem of course is that you can’t just add a gene, you need to get it from a breed that already has lavender.
Theoretically what you do is fairly simple, it will just take a long time, lots of birds and lots of hard culling. For example to create a lavender leghorn,
- Mate a black Leghorn with a lavender Araucana. The F1 will all be
- Black but carrying the lav gene
- Showing pea combs and blue eggs because they are dominant but heterozygous (split) for them,
- Legs are a bit trickier depending on the genetics of the Araucana parent.
- A weird build because they are crosses.
- Around a quarter who are lavender, half lav carriers who look black and the rest black with no lav.
- Around a quarter with a straight comb and white eggs, half with the hybrid comb and blue eggs, and a quarter who are homozygous for the pea comb and eggs.
- Some with yellow legs.
- After 2 generations, your birds are around 50% Leghorn.
- After 4 generations, they’ll be about 75%,
- after 6, 87.5%,
- 8 – 93.75%,
- 10 – 96.875%,
- 12 – 98.4375%
Given that Araucana and Leghorn both have a light build and you are purposely selecting the chicks to be Leghorn-like, they will probably look like Leghorns fairly quickly – those numbers are averages. But the more generations you can do it for, the better they will breed true and the fewer weird crosses you will get, because you will have culled those genes out.
The goal of any breeding program can’t be the look of a particular bird – it is how well that bird can pass that look on to further generations. And for that, you need it to be as homozygous as you can get it, rather than a lucky fluke.