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Original
Article About Dexters
"The
Significance of an Achondroplasia-Like Condition Met With in Cattle"
by F.A.E. Crew
in Proceedings of the Royal Society of London,
volume 95, 1923, pages 228-255.
This is a historic study of the genetics of the bulldog calf problem in
Dexters. In 2003, an Australian researcher finally identified the gene
causing the bulldog calf, a condition now known as chondrodysplasia. A DNA
test now enables Dexter breeders completely to avoid bulldog calves. Crew's
article is out-of-date scientifically, but it contains interesting historic
information about Dexters, as well as an indication of both the tragedy of
the bulldog calf and the confusion that Dexter breeders faced in trying to
eradicate it.
CONTENTS
I - The Dexter
II - The
Genetic Constitution of the Modern Dexter
III - The
Monstrous Calf of the Dexter
IV -The
Pathology of the Monstrous Calf
V - Diagnosis
VI - The
Etiology of Achondroplasia
VII - The
Significance of the Monstrous Calf
VIII -
Suggestion as to Methods by which the Monstrous Calf might be Eradicated
IX - The
Possible Bearing of the Case of the Monstrous Calf of the Dexter Upon the
Species Question
Summary
and Bibliography
Photographic Plates
Page 228:
I -The Dexter
The Dexter is a breed of the smallest cattle in Great Britain. Formerly it
was indigenous to the south and south-western districts of Ireland, but of
late years it has become increasingly popular in England.
Its general appearance, as defined in the terms of the standard of
excellence laid down in the Kerry and Dexter Herdbook, is as follows:
Page 229
Head short and broad, with great width between the eyes and tapering
gracefully towards the muzzle which should be large with wide distended
nostrils. Eyes bright, prominent, and of a kind and placid expression. Neck
short, thick, and deep, and well set into the shoulders, which, when viewed
in front, should be wide, showing thickness through the heart, the breast
coming well forward.
Horns - These should be short and moderately thick springing from the
head with an inward and slightly upward curve.
Body - Shoulders of medium thickness, full and well filled in behind;
hips wide, quarters thick and deep and well-sprung, flat and wide across the
loins, well ribbed-up, straight underline, udder well forward and broad
behind, with well placed teats of moderate size; legs short (especially from
knee to fetlock), strong, and well placed under the body, which should be as
close to the ground as possible. Tail well set on and level with the back.
Skin - The skin should be soft and mellow, and handle well, not too
thin; hair fine, plentiful and silky.
Coat colour - Bulls, whole black or whole red (the two colours being
of equal merit). A little white on the organs of generation not to
disqualify an animal which answers all other essentials of this standard
description. Cows, black or red (the two colours being of equal merit).
White on udder and the extension of white on udder slightly along inside of
flank or underside of the belly, or white on tassel of tail, may be allowed
on an animal which answers all other essentials of this standard
description.
Weight - Bulls should not exceed 900 lbs., live weight, when in
breeding condition. Cows should not exceed 800 lbs.
In view of that which is to follow, it is desired to call attention to these
two characters of the ideal Dexter—brachycephaly and micromelia.
Two undesirable characters are encountered occasionally, “bad tail-head,”
the tail not being terminal but seeming to take origin further forward along
the back and arching upwards and backwards, and a combination of bent
forelegs with inwardly turned hoofs. “Its toes turn in after a peculiar
fashion, and it tends to walk over the outer digits, especially in the case
of the hind feet.”
The history of the Dexter is wrapped up in that of the Kerry, and like that
of almost every breed is befogged by anecdote and speculation. It is
generally accepted that the Dexter is an offshoot of the Kerry; it is
certain that the breed has arisen out of the old-fashioned Kerry stock as a
result of an outcross.
Page 230
The native ancestral stock from which the modern Kerry has been developed
was a black-coated race, being of the same stock as the native Celtic cattle
of Great Britain. The modern Kerry is all that remains of the race which in
former days was to be found throughout the whole length and breadth of
Ireland. There are historical records of the importation of Longhorns,
Shorthorns, Herefords, and Devons into Ireland, and by the middle of the
nineteenth century the old native race as such had become almost entirely
replaced by imported stock, and was extinct in all parts save in Kerry and
Donegal.
Wilson has given an exhaustive survey of the literature which bears upon the
origin of the Dexter breed and upon the manner in which it got its name. He
concluded that the early records of the Dexter herd are unreliable, and that
a better idea of its ancestry can be derived from the genetical analysis of
the modern Dexter.
On to Part II
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