Download Dwarfism In Miniature Cattle: What You Need to

Dwarfism In Miniature Cattle: What You Need to Know
Let’s clear up some murky areas about dwarfism in miniature Hereford cattle. I’ve
heard it all too often when some old cowman or an uniformed individual hears that we
raise miniature Hereford cattle, “Oh those dwarfs?” usually with a very disapproving
look on their face. There is no denying that dwarfism is part of the history of
Hereford cattle in America.
However, dwarfism is also part of Angus and Short
Horn history, and the reason that dwarfism has
seemingly become a Hereford “trait” is because
Hereford cattle were by and far the most popular breed
in America during the “dwarfism storm” of the 19501960s. It is sad to me that—so many years after
advanced science has disproven some of the myths and
fables of dwarfism—I still hear things like “that
dished-faced cow looks dwarfy.”
The fact of the matter is that The American Hereford Association faced the dwarfism
crisis head on and went to work trying to trace dwarfism back to its origins and also to
clear pedigreed lines of cattle. Eventually the recessive gene for dwarfism was traced
back to a 1900s bull named St. Louis Lad. By the 1970s a combination of rigorous
pedigree checking and also The American Hereford Association’s transparency and
willingness to work with universities had all but genetically fixed the dwarfism crisis.
Several stigmas arose from the time period, though: first, that bigger was obviously
better, and secondly that white-faced cattle would unfairly be looked upon as
genetically dirty.
Right now any A.H.A registered Hereford in America, whether it be a little 0000
frame score or a big 7 frame score, has been certified to be free of the dwarfism gene.
The recessive trait no longer exists in REGISTRERED Hereford cattle. Any
registered Hereford can have her royal history traced back through the A.H.A for over
100 years. Miniature Herefords are not genetically distinguishable from commercial
Herefords; they are the exact same cattle—just in a smaller, more compact size.
Cattle carrying the dwarfism trait were never used in the creation of The Miniature
Hereford, which is really not a separate breed, merely a smaller frame score. This
brings up another subject that needs to be addressed pertaining to miniature cattle in
general though.
Dexter cattle, which are purported by some to “be the only true miniature cattle,” are
actually genetically dwarves. Dexter cattle present a unique genetic situation: Dexters
carry a dominant gene mutation that essentially defines Dexters as a breed (ie the
short legs). Most Dexter cattle will not breed true to size due to this gene, and this is
why two different “types” of adult Dexter cattle exist: the long-legged Dexters and the
short-legged Dexters. Short-legged Dexters are considered the “true” Dexters but
these cattle are often, if not always, heterozygous (meaning they carry one copy of the
gene) for the dwarfism gene. The short-legged version was and continues to be the
desirable type of Dexter. If two heterozygous Dexter cattle are mated there is a 25%
chance that a long-legged calf (a calf not
carrying the dwarfism-causing gene) will be
born, there is a 50% chance that another
heterozygous short-legged Dexter will result,
and a 25% chance that a “bulldog” calf will be
produced. The homozygous state that results in
bulldog calves is always lethal; calves are either
aborted early in term or are delivered full term
with mass developmental abnormalities.
So why is any of this important, you raise Registered Miniature Herefords? The first
reason is that many people like to lump miniature cattle into a broad category. To
them, there are not Low Lines, Miniature Herefords, Dexters, etc.; they are all just
miniature cattle. There needs to be awareness that there are distinct differences
between breeds, just as there are in commercial cattle.
Secondly, the beginning of commercial miniature herds is on the horizon. A lot of
these producers use Low Line and Miniature Hereford genetics to produce the
splendid little F1 baldy cow. However, some producers are incorporating Dexter
genetics into these commercial miniature herds, and it has already been shown in
history what dwarfism can do to a breed of cattle.
The Low Lines and Miniature Herefords do not need the black eye of dwarfism
mistakenly placed on them because of Dexter blood in commercial miniature herds.
Responsible Dexter cattle breeders across the country are beginning to take action, but
there are many that continue to propagate the genetics that are responsible for
dwarfism within the breed. Dexter cattle were originally, unknowingly, bred from
dwarf stock to produce more dwarf stock. Miniature Herefords and Low Lines were
not bred from dwarf stock nor has dwarfism ever been introduced to either breed to
reduce size.
If you are looking at buying miniature cattle either to start a herd or add to one, get
informed about the breed that you intend to purchase and always purchase cattle from
a reputable and responsible breeder.
Britt Whitt
C.S.U. DVM Class of 2013