If you have not read my previous post called “Working with the gold / silver gene”, I recommend reading that first, as this post builds on the concepts of the sexlinked silver gene.
Is it possible to use 2 different sexlinked genes at the same time? Of course! There is no linkage between the silver gene (used for red sexlinks) and the barred gene (used for black sexlinks). This won’t use both genes for sexing, though it is possible to do that (more on that later).
In this example, we will be using autosexing chickens, specifically welbars. The genes needed to make a line of chickens autosexing are 1) wild type chick down (partridge, black breasted red) and 2) sexlinked barring. Some other genes can interfere with autosexing, but some genes are compatible with the autosexing combination. Silver is compatible. Most autosexing breeds are gold-based, for example Legbars and Bielefelders. Welbars are gold-based in their original form, but silver has been added to some lines (though it is still rare). I have heard of the existence of Silver Bielefelders, and I think it would be fairly easy to create a line of Silver Biels if you had a silver Welbar to cross into the Biels.
So, Welbars are well established as autosexing, and available in both silver and gold. They remain easily sexable no matter which silver/gold genes they possess. So you can use the examples in the previous post with Welbars to create a pen that produces both silver and gold chicks. This is great if you are selling chicks, as most customers want some of each color.
If you use a silver pullet and a gold cockerel, you will get red sexlinks, where all the pullet chicks are gold and all the cockerels are silver. This is a fun experiment to prove how sexlink genes work. It does not help if you want to produce more silver pullets, but the cockerels from this cross are heterozygous for gold, so if you cross the F1’s, you will get both gold and silver pullets and cockerels, that are still sexable at hatch (because they are autosexing). This is much better than you can get from the commercial red sexlinks, where the F2 is not sexable at all.
As you build a breeding pen of Welbars to produce both gold and silver pullet chicks, keep in mind that only the genetics of the cockerels matter in regard to the proportion of gold to silver pullet chicks.
- Gold cock – all pullet chicks are gold
- Silver cock that is homozygous for silver (no gold gene) – all pullet chicks are silver
- Silver cock that is heterozygous for silver (1 gold gene) – pullet chicks are about half silver, the rest gold
Best pen for producing salable Welbars chicks
Gold pullet with a Silver cock that is heterozygous for silver. This is a self-sustaining group. When you want to raise replacement breeders, keep gold pullets and silver cockerels. All the silver cockerels from this mating will be heterozygous for gold. If you keep silver pullets in this pen, you might consider separating the best looking gold pullets for a time and raise cockerels only from their eggs. You don’t need many replacement cockerels, so this should be doable.