In-breeding

In-breeding or maintaining a closed flock keeps a high level of genetic uniformity. You pretty much know what you are going to get from a closed flock: more of the same. Following the old engineer’s saying, "If it ain’t broke don’t fix it!", successful exhibitors are reluctant to introduce unrelated stock into their strains because they fear, correctly, that although the birds so bred may be more vigorous and fertile than their in-bred birds, they will be much less perfectly marked or much too big to be an acceptable show bantam.

In-breeding depression or in-breeding degeneration is the inevitable result of many generations of close in-breeding. It is where there has been a great deal of mating between close relatives. Most breeders of Sebrights, for example, have to contend with poor egg production and fertility, and the few chicks hatched are very delicate. But, a Sebright is a very precise bird. The lacing of the feathers, the comb, and the size and type of the bird all have to be correct, otherwise it is not worth having. Luckily, some European bred Sebrights are now available here, so our breeders at last have some suitable fresh stock to use. Even so, I am sure they will wing-tab and/or leg-ring all chicks very carefully so they know which are original strains and which are from the new stock.

Most of the harmful genes causing problems are recessive, as distinct from dominant. In other words, they tend not to manifest unless they are inherited from both parents. In populations where birds (or animals or people) which are not related are producing young, then it is very bad luck indeed if a mating pair has the same harmful, recessive genes. The harmful genes of each parent are usually prevented from operating by the good, dominant genes of the other. In closed populations there is a greatly increased risk that both parents will be carrying the same harmful, recessive genes (but masked and therefore undetectable), thus producing 25% with the faulty genes operating, and a further 50% with a single faulty, recessive gene to carry on to future generations.

Closed flocks

Closed flocks can be perpetuated for an extended period - even decades or more - by keeping as large a flock as possible, and with good organisation, taking care to mate cousins rather than siblings. In an ideal arrangement, as might be employed by a commercial operation, there would be six or eight breeding pens of a strain, with the cockerels from pen A being bred to the pullets from pen B, and so on. Hobbyist breeders will usually have to make do with three or four pens, and keep as many cockerels as possible in order to maintain as wide a genetic pool as possible within the strain. This is why most of the famous names in our hobby are specialists. They understand why it is necessary to keep a large flock of nearly identical birds. This is often lost on beginners who, after visiting an expert, are probably thinking, "That was a bit boring. I’d rather have lots of different kinds, with just a few of each".

Line breeding

Line breeding is a form of in-breeding where maximum use is made of one outstanding individual. The rotational mating of a large, closed flock is what is necessary to keep a very good strain going. Line breeding is what went on before. Imagine if you have bought a trio, have bred a good bunch and one of the cockerels has won some Best in Show awards. The obvious next step is to breed from him, and the following year to breed from him and his daughters. If he lives that long, continue with his grand-daughters and great grand-daughters. You will gradually be building up the numbers so that by the time the original champion goes off to the great free-range in the sky, you will have enough birds to switch to the rotational system above. This, with careful selection and some luck will be the foundation of a succession of future champions. The aim of breeding for the shows should not be a Holy Grail style quest for the perfect specimen, but rather many years of regularly being ‘in the cards’ at the shows.

Out-breeding

Out-breeding or out-crossing is where very unrelated strains are bred together. It may be done to rejuvenate an overly in-bred strain, as illustrated in the Sebright example referred to earlier. In this case, after the outcross, it is then back to in-breeding as normal for the next few years. Where the production of utility birds is concerned, it will be used regularly. If you were thinking of producing ‘laying bantams’ for sale, most likely with Araucanas, Marans, Welsummers or Welbars, then the best method would be to develop two separate in-bred strains of whichever breed it is. The productive layers would be strain crosses between these two lines. This is the method used to make commercial ‘hybrids’.

Maximum hybrid vigour is only obtained in F1 stock from in-bred parents. (F1 stock is a hybrid strain from the careful crossings of pure-bred parents of the same breed, giving uniformity and vigour). Quite a large scale operation is needed to do this properly, with very careful record keeping so that the parentage of every egg and chick is known. This is why no-one, as far as I am aware, produces utility bantams.

Upgrading

Upgrading has most often been used in ‘third world’ countries to improve indigenous stocks, in so far as the local climatic and disease conditions allow. Highly productive American and European poultry (or other livestock) often sicken and die in the tropics, but crosses of three-quarter breds with local breeds give a practical compromise between productivity and survivability. For hobbyist poultry keepers, this process is used as an emergency measure with nearly extinct, rare breeds. In the 1960s, poultry breeder Rex Woods bought most of the surviving large Spanish and crossed them with Minorcas. This was followed by more back-crosses to Spanish, to produce a vigorous population of nearly pure White-faced Spanish.

Cross-breeding

Cross-breeding is the mating of one pure breed with another. It is not normally done in bantam breeding, unless in an emergency (as with the Spanish example above), or when a new breed is being made. As there are already more than enough recognised varieties for the world’s bantam breeders to keep going, it is not something that is generally advocated. In many cases, there is no point as it is highly likely that the breed clubs would not recognise a new creation.
There are a few varieties of bantam which would be acceptable as they already exist as large fowl, but have not yet been bantamised. Examples to consider include Cuckoo, Dark, Red and White Dorkings, Gold and Silver Campines, Ixworths, La Fleche or Modern Langshans.

In the case of the Dorkings, the initial cross would be between under-sized large Dorkings of whichever colour is to be made, and Silver Grey Dorking bantams, the only colour currently existing. After about five years of breeding many, and just breeding from the best, the result should be reasonable but not yet perfect specimens.

The same process, one or two initial crosses followed by years producing large numbers of chicks from which only a small proportion will be used for breeding, will be used for the other suggested ‘new’ breeds. In all cases, one parent will be the smallest available specimen of the large breed. For the other parents, I suggest Brakels and Pencilled Hamburghs for Campines, White Sussex, Jubilee Game and White Ko-Shamo for Ixworths. For La Fleche, use Black Minorcas first, followed by Black Rosecombs. Rosecombs are too small to mate with a large La Fleche.

In the case of Modern Langshans you may not be able to find any large ones, so start with a Croad Langshan bantam x Black Modern Game mating.

As all these projects involve producing a lot of unwanted birds, be prepared to eat a lot of cockerels, and have a lot of cross-bred pullets to sell as layers.

The genetics of poultry will have to be studied in depth. You will need an up-to-date book, for much has been discovered recently. Dr Clive Carefoot, in particular, has proved that a lot of the old text books were wrong on the partridge, pencilled and double-laced patterns.

© Copyright 2003. David Scrivener