There is a fear of inbreeding in chickens that I believe may be less common than you would expect, but given the bad outcome, it is worth thinking about how you can prevent or delay inbreeding when planning your breeding program. I am always short of pens, so I give a lot of thought to how I can create with fewer pens. This is an explanation of how one could maintain 2 colors of a breed for the long term with very limited inbreeding. It takes advantage of the sex linked silver/gold gene, but could be adapted to other colors or traits. The important part is that you are using the same breed and complimentary colors. I am using Wyandottes as an example, but this would also work great with Cochins, Polish, etc.
Pen layout
- Pen 1 – Gold laced Wyandottes
- Pen 2 – Silver laced Wyandottes
- Pen 3 – Silver laced Wyandotte hens, Gold laced cock
Management
The first 2 pens produce pure colors of both sexes, the 3rd pen produces sexlinked Gold laced pullets (you can probably sell these easily), Silver chicks are males, but are heterozygous for gold. Cull or sell these for meat production.
After a few years (it usually takes several to many generations before you see any inbreeding depression in chickens), raise the chicks from pen 3 and replace their counterparts in pen 1 and 2. Pen 2 will produce some (50%) gold laced chicks. Raise those as replacement cockerels (and pullets if you need them) for pen 1. From now on, pen 2 may have “contaminated” cockerels that produce some gold chicks, but this is not a huge problem, as you will still get plenty of silver pullets to refresh pen 3 whenever you want.
This setup produces salable pullet chicks (sexed chicks bring several times more than straight run) from pen 3, a good way to help offset feed costs. Small breeders producing sexable chicks of heritage breeds is quite rare, so if you pick a popular heritage breed, like Wyandottes or Cochins, you should be able to easily sell all the pullet chicks you produce.
Genetics of the pens
Pen 1 (all gold) – Gold is a sexlinked recessive allele, so this pen is always 100% pure for gold. No silver genes ever exist in this pen, making breeding straight forward. You can raise replacement stock from the chicks from this pen, or take gold chicks from the other pens.
Pen 2 (all silver) – Silver is sexlinked dominant, so silver females are always pure, but males can carry a copy of the recessive gold gene. If the male is heterozygous for gold, then half of the pullet chicks will be gold, and they will be pure (no silver) and can be used as breeders in pen 1. The male chicks will all be silver (making any gold chicks from this pen 100% females – you cannot produce a gold male with silver females as the parent). If the father is heterozygous for gold, the half his sons will be also, but you will not be able to distinguish them from the homozygous males. When you start with all silvers, you could only use silver cocks from this pen to replace their father, ensuring the cocks always remain homozygous. This seems like a “cleaner” solution than to mix in cocks from pen 3 that are heterozygous, but unless producing extra gold chicks is a problem, the ability to get gold pullet chicks from this pen is an advantage.
Pen 3 (sexlinked producing) – This is the pen where you start mixing the 2 colors, and where you get all sexable chicks to sell. Logically, you might want this pen to have the largest breeder flock, to maximize the number of chicks you can sell.
Final thoughts
I picked gold and silver laced as the colors here because that color pattern is beautiful and in demand. Gold laced pullets should be in high demand. But you could do this same breeding strategy with other color combinations as well. The other sexlinked gene that is common in many breeds is barring/cuckoo. That can be used to make black sexlinks, and the process could be made to work the same way, but it is perhaps a bit easier to manage because sexlinked barring is partially dominant, meaning that heterozygous males look different than homozygous males.