Autosexing Breeds

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In 1858 Charles Darwin published 'On the Origins of Species by Means of Natural Selection' sparking off a revolution against the established view on the creation and development of of all living creatures; Gregor Mendel, a Czechoslovakian monk born in 1822, took great interest in the ideas of 'Darwinism' and in 1866 following extensive experiments using peas, published his findings on inheritance, which today we know as "Mendel's Laws of Inheritance".

Mendel's work received very little interest primarily because it was published in a university journal with very limited circulation. Two years later Mendel was made Abbott of the monastery, and his research work was greatly curtailed; when he died in 1884 there was still little recognition of his work and it is reputed that following his death all his papers and the records of his work were burned by the monastery. In the years following Mendel's death details of his work continued to spread, and the importance of his findings finally realised.

In 1900 the British scholar Professor William Bateson of Cambridge University re-presented Mendel's paper to the Royal Horticultural Society in London; Bateson coined the word 'genetics' and was instrumental in bringing Mendel's Laws of Heredity to the attention of English speaking scientists. One of his greatest disciples was Reginald Crundall Punnett who was born in 1875. Punnett was interested in Mendelian ex

perimentation with both plants and animals and between 1904 and 1910 collaborated with Professor Bateson at Cambridge University on hybridization experiments with sweet peas and poultry: their research greatly extended the knowledge and understanding of the importance of Mendelian genetics.

In 1905 Reginald Punnett published a textbook on Mendelism, and introduced the now widely used "Punnett square" a chequer board depicting the number and variety of genetic combinations. In addition to his scientific research Punnett had a great interest in poultry breeding and during World War I advised the Government on all aspect of poultry breeding. In 1910 he became Professor of Biology at Cambridge and in 1912 became Professor of Genetics, the first in Britain. As a consequence of his research with poultry Professor Punnett wrote 'Heredity in Poultry' which was published in 1923 and was the standard work on poultry genetics for many years.

During the late 1920's Professor Reginald C Punnett identified a sex-linkage between gold males and silver females; if, for example, eggs from a Rhode Island Red cock (gold) and Light Sussex hens (silver) are hatched all the pullets will be a darker gold in colour and the cockerels a pale yellow. Punnett subsequently identified a sex-linked barred feather pattern and as a direct result of these two factors instigated a series of breeding programs to investigate the possibilities of utilising this knowledge for practical purposes, the result of which were the Autosexing Breeds.

During the 1920's and 30's Professor Punnett and his team at Cambridge developed several autosexing breeds following the creation of the Cambar in 1929; whilst elsewhere in Britain and the rest of the World, other universities and individual breeders took onboard the newly found knowledge and developed more autosexing breeds. In 1943 the Autosexing Breeds Association was formed demonstrating the commercial importance of the new breeds, yet in 1967, less than 25 years after it's formation the ABA was disbanded. Professor Punnett retired in 1940, at the age of 75, though he continued his research into poultry genetics well into the 1950's and died in 1967 at the grand age of 92 years.

Before World War II almost all poultry in Britain, and else where in the World, even on commercial scale, were either pure breeds, or a first cross between two breeds; large scale commercial hybrid strains were unknown, so the research at Cambridge into autosexing had been in line with the idea of farming using pure breeds.The need for the autosexing breeds had run it's course and poultry farming around the world had changed dramatically; the use of modern commercial hybrids replaced the use of pure breeds as commercial layers and meat birds, and during the late 1930's and early 1940's poultry farming around the word was revolutionised, by the introduction of large scale electric forced-draught incubators and the development of day-old chick vent-sexing techniques by the Japanese. However even today the developers and producers of many commercial hybrids still utilise autosexing techniques in their breeding programmes.

Much of Professor Punnett's work in the creation of autosexing breeds had been based on barred plumage, and numerous crosses were made using the Barred Plymouth Rock, a very popular utility breed of the day, from these crosses Punnett & his team had successfully proved not only the theory but had also created a small group of Autosexing breeds. The 'barring' pattern is sex-linked, the cockerels having two chromosomes and the pullets only one, this results in the chicks of a barred breed have a light coloured patch on the top of the head; in chicks with black down both sexes are very similar and sexing at this stage will not be 100% accurate. However, when the barring is combined with brown colouring the light colored spot on the head of the pullets is small and clearly defined, and in addition there is a very clearly defined stripe down the body. The cockerels on the other-hand have a light patch covering most of the head and there is only a very blurred, indistinct body stripe, overall the down is much paler - the differences between the sexes at day old are very obvious and enable 100% accuracy. Because the ability to sex chicks of the Autosexing Breeds straight from the incubator is such an important factor many of their Breed Standards contain description of the down colouring in addition to the adult plumage.

The Autosexing breeds were given somewhat uninspiring names reflecting their origins:

It is important to remember that these autosexing breeds were established as breeds, they are neither cross-breds nor hybrids, but are genuinely pure-breeding breeds.

The Poultry Club of Great Britain approved individual Breed Standards for them, but they have never 'taken off' as exhibition varieties, and are extremely unlikely to do so now. Today these breeds, created for practical utility purposes, have all but disappeared. The UK National Database for AnGR (Animal Genetic Resources) in the UK Country Report on Farm Animal Genetic Resources 2002 published by DEFRA provides the following information :

From where the data was obtained is unclear, but there appears to be some question as to the accuracy of the data for the Cream Crested Legbar is the most popular of the autosexing breeds and is certainly far more plentiful than the Welbar. It is possible to identify many breeders with the Cream Legbar, but the Welbar is certainly as scarce as the Rhodebar, and the number of breeders can be counted on one hand. However what is true is that all the Autosexing breeds with theexception of the Cream Legbar are now rare and in danger of extinction; of course it would be quite possible to re-create them - assuming that the original component breeds have not been lost as well. It is important that this valuable genetic material is maintained ....... maybe they still have there uses, and maybe, just maybe, they will be wanted again one day ......

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