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Duck Colour
Genetics - Book Review by FM Lancaster
COLOUR
BREEDING IN DOMESTIC DUCKS
by Mike and Chris Ashton
More info
In
my early days of duck breeding in the 1950s I was always very envious
of budgerigar
fanciers.
Based on earlier work done by Dr H. Duncker, the Budgerigar
Society produced a booklet entitled ‘Budgerigar Matings and Colour
Expectations’.
It contained lists of all the known colour genes and details of
nearly 2,000 matings designed to produce every possible colour and
pattern combination.
With Mike and Chris Ashton’s new booklet, duck breeders now
have their very own breeder’s manual.
Most of the early work on duck colour genetics by George Jaap,
R.C. Punnett and others was published in obscure scientific journals and
was not readily available to duck breeders.
In spite of this, some of the early pioneers, like Mrs A.
Campbell and William Cook, and more recently Will Bradley, Reginald
Appleyard and Leslie Bonnett, managed to create some useful new breeds,
with very little knowledge of genetics, by trial and error.
In the 1960s I tried to bring together all the known
information then available on this subject.
The difficulty was that the number of duck breeds and colour
varieties extant in the
U.K.
was very limited.
Hardly any new breeding and development work had been done since
before the war because of food rationing, and no new birds had been
imported from overseas because of wartime restrictions and fowl pest
regulations.
In the last 30 years the number of breeds has increased rapidly
as a result of introductions from abroad and new creations.
The Ashton booklet has made full use of this new resource and
widened our knowledge of plumage colour genetics in ducks.
The authors of this publication are eminently qualified for this
task since they have not only made an intensive study of duck genetics
but also have nearly 30 years practical experience of waterfowl
breeding.
The other innovation which makes this treatise so unique is the
number and quality of the colour photographs, which are truly
magnificent.
The booklet is divided into five sections. The first deals with
basic genetics in an easily understandable form.
The effects of all the known colour and pattern genes in ducks
are then described together with their modes of inheritance and a list
of breeds carrying them is provided.
The second section describes the appearance of the various breeds
and colour varieties in greater detail under ten major headings.
This is supported by spectacular colour photographs of ducklings,
and adults of both sexes.
I particularly liked the pictures of the wings of various breeds
showing the specula and wing coverts etc. in great detail.
Quite a few of the breeds are recent acquisitions from
Continental Europe, and in this respect the work has a truly
international relevance.
The third section on sex-linkage is understandably quite short
since only two sex-linked loci are known in the common duck.
Also sex-linkage does not have the same economic importance in
ducks as in chickens and turkeys since vent sexing in ducks is
relatively easy to learn.
Section number four digresses slightly, and deals with some of
Punnett’s early experiments with sex-linked brown dilution and
explains its effect when combined with the two pattern loci, M+
and Li+
The last section, in terms of advice, is probably the most
important of the whole work.
It points out the major pitfalls encountered in producing new
breeds and revitalising old ones.
Most breeders know about recessive genes, but many are unaware of
another ‘hidden’ group, hypostatic
genes, which are prevented from expressing themselves by the
presence of other (epistatic) genes at different loci.
The two main epistatic genes in ducks are recessive white (c) and
dominant extended black (E) which both mask the presence of most other
colour and pattern genes.
In fact, c is even epistatic to E when in the homozygous state
(cc). The
authors explain at length the difficulties encountered in using breeds
carrying these epistatic genes.
They also enlarge on the complex interactions between the two
triple series controlling variations in the basic ‘wild mallard’
pattern.
Throughout this section, they are to be commended for pointing
out when their breeding results have disagreed with those of earlier
workers, in terms of degrees of dominance and other gene interactions.
With the wider range of modern breeds it is to be expected that
some genes will behave differently against a different genetic
background.
In this respect they have updated our knowledge of colour
genetics in the duck and brought it into the 21st century.
The final conclusion gives some very sound advice:
Never produce a new breed or variety and release it to the public
without adequate progeny testing to remove
unwanted recessive genes.
It is a great temptation on creating something new and exciting
to release it too soon.
This is unfair to other breeders and can only harm one’s
reputation.
The work ends with a chronology of reported mutations in
Britain
and a useful glossary and list of references.
I can thoroughly recommend this scholarly publication and suggest
it should be an essential part of every ornamental, exhibition and even
commercial, duck breeder’s library.
F.M.Lancaster
These books are available from
Amazon
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