National Clan Breeding Project


We will not achieve improved strains of stock through haphazard, free-for-all matings. There MUST be a plan. A well thought out Clan Breeding System is the answer but for those of you that have been Line Breeding for years read on and let us persuade you that Clan Breeding IS THE BEST way forward for the conservation of rare breeds.

The gene pool of any population must remain as diverse as possible if it is to respond to challenges in its environment. For improvement breeding, likewise, the greater the genetic diversity we maintain in the flock, the greater the chance that the traits we are targeting will express in the offspring and be available for selection.

We need a mating system that combines rigour with practicality, that avoids breeding individuals that are too closely related while maximising genetic diversity within the breeding pool and reducing record keeping to an acceptable minimum.

What is a breeding programme anyway?

A breeding programme is a reasoned method of breeding that is followed for a number of years with specific aims such as increasing egg production, fertility, egg size, colour, body weight or selecting for other desirable traits. Haphazard breeding will result in haphazard results.

Line Breeding

Line Breeding is the most common form of breeding programme used in the poultry world. It is the practice of breeding father to daughter or mother to son effectively inbreeding. This is usually a better practice than breeding siblings that are more related to each other than to either of their parents and can be a good way to establish a breeding flock if you only have one unrelated pair to work with but Inbreeding is the natural consequence of Line Breeding related stock year after year.

In the same way as you can select for good traits you can also inadvertently be selecting for bad, and less noticeable, traits like poor egg production, lack of vigour and size. If birds become too closely related, then vigour and hatchability will suffer. The degree of inbreeding (how close the relatives are) will determine how soon you will see these problems.

Line Breeding only really works when you start from a good place with well- bred birds that meet breed standard.

The 7 target breeds are not in that place.

Clan Breeding

Clan Breeding is a way of maintaining a closed flock (bringing nothing in from outside) for very many years without the problems of inbreeding. Clan Breeding is the opposite of Line Breeding because the father and daughter will never mate and neither should the mother and son. Clan Breeding requires at least 3 breeding pens of the same breed. In a nutshell, a clan is a flock of related females that always stay in the same pen. All chicks (male and female) take the clan of their mother, the cockerels are used only once in each pen and never return to the same pen. After year 2 they are culled or sold. A reserve cockerel is chosen from each pen as and when needed but will never mate with the pen in which he is born. The result is that without much thought, you can ensure your breeding pairs are not too closely related and you can focus on what the birds look like and how close they are to the breed standard, breeding good numbers and selecting well.

Where to start – establishing the Clans

Select your initial stock. This will generally be determined by the number of unrelated cockerels you have. If you have just one cockerel you will have one clan, 2 unrelated cockerels 2 clans etc. Name the clans with a name and A, B, C etc

If you are an experienced breeder you may have already established pens of separate strains or blood lines and this is a perfect place to start. You may have been Line Breeding or just picking the best from each pen each year. Pick your best and most diverse birds. You may know how they are related to each other so keep those breeding lines separate if possible.

Imagine after selection we have six breeding birds, three hens and three cocks. Although in reality you could start with three trios or 3 quads. We assign each hen and each cock to one of three clans let’s call them Red, Green and Blue (in that order). We might have good reason for assigning breeding stock to one clan rather than another, but the initial assignment can be entirely arbitrary. Once assigned, however, each bird remains in its designated clan for life.

Red Group A Clan (red ring) Green Group B Clan (Green ring) Blue Group C Clan (blue ring)

But what if I only have a single pair or are new to the breed and don’t have much space?

A Clan Breeding project can start with a just a pair mating to establish the clans and to understand the genetics of the parent stock. If you have just one pair in Year 1 mate that pair. In Year 2 mate the best (F1) cockerel (son) back to his Mother. In Year 3 mate the same F1 cockerel (now the father) to his best daughters (F2) of the Year 2 mating. From the resulting progeny pick the best 3 pairs to start your 3 clans, Red, Green, Blue. Alternatively, work with another breeder or more so that together you produce 3 Clans.


On hatch ALL chicks must be wing tagged for identification. Coloured leg rings are also useful to identify each clan. Assign all chicks, cockerels and pullets, to the clan of their mother.

Any progeny defective (comb defect, wrong colour legs, late feathering, lack of vigour compared to growth of the others) are culled early. The rest are allowed to mature to 6 months and then hard cull decisions are made to select one possibly two males (reserve cockerels) and as many good females as there are from each Clan. The males are retained as replacements, always retaining the Clan identification.


In breeding season 2 all cocks move to the next Clan over. For those of you with just one or 2 Clans you will be placed in a group to share resources and swop cockerels! The aim is that we spread as many of the genes across the entire country as we can.

The importance of assigning chicks to the clan of their mother becomes clear. The progeny of Red mothers have Blue fathers, hatches from Green hens have Red fathers, etc. But all chicks take the clan of their mother and remain in it for life to prevent close mating. Use coloured rings on the right leg to indicate the Clan colour at a glance.

Again, cull hard. Retain just one or two cockerels from each Clan pen as replacements.

Outside of the breeding season all hens can run together. Coloured leg rings make the job of separating them in time for the next breeding season easy. Allow at least 3 weeks for the hens to be clear of any other cockerel’s sperm before collecting eggs.

BREEDING SEASON 3 and in all future seasons

The Rules

- If a cockerel from the Red Clan (for example) needs replacing, he MUST be replaced with a reserve cockerel from the Red Clan.

- Cockerels only ever mate hens in the next clan over (after year 1) and never go back into the clan in which they were born to prevent sibling mating.

- Use cockerels for one year only to prevent father-daughter mating

- Never mix the Clans or be tempted to use a cockerel from the incorrect Clan even if he is better than the selection from the correct clan

As long as you follow this scheme, there will never be a mating between siblings or half-siblings in your flock, and genetic diversity will remain as great as it can possibly be, at least without tracking individual pedigrees in much greater detail.

However, note that, if cocks are retained for more than one breeding season, it is possible an older cock could breed his daughter from the previous year. Such father-daughter mating’s are impossible if cocks are used for one breeding season only.

We believe that this is the best way to proceed to improve vigour, health and vitality in these extremely rare breeds. We believe it is a system that enables reasoned selection for the most desirable traits ensuring that inbreeding risk is minimised, and rare but important traits are not lost, while breeding to standard particularly in relation to type. We commend this breeding method to you and your breeders as a way to encourage new breeders to get involved and to make a real difference to conservation no matter how small the contribution they can make.

Serena Eustice

Breed Registrar Marsh Daisy

Paul Morgan

Breed Registrar Spanish

March 2021

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