What about Chondrodysplasia?
Chondrodysplasia is a genetic issue, not contagious, and not a disease. It is a kind of
dwarfism present in the Dexter breed, just as many breeds have a form of dwarfism. Not
all Dexters carry the gene for this kind of dwarfism, and there is a DNA test now
available which makes it easier to know which animals carry it and which don'talthough
experienced breeders have been able to guesstimate for many years (with varying degrees
of success) by looking at an animal. It is probably this visual method of trying to
distinguish which gave rise to the terms "shortleg" and "longleg" Dexters. The body
type of the "shortleg" Dexter is often "beefier" and shorter; chondrodysplasia carriers
typically have this body type, but not all Dexters with this body type and short legs
are chondrodysplasia carriers. This is the reason I try to call my cattle which carry
this gene "carriers," or even better "chondro-carriers." Others call them "dwarfs,"
"shortlegs," or "affected." The Dexters which do not have the gene at all are called
"non-carriers" of chondro (my preference), or "normal," or "longleg," or
"homozygous normal" or "unaffected."
The "bulldog" calf, a non-viable fetus/newborn, results from the calf inheriting this
chondrodysplasia gene from BOTH parents. The statistical probability of a calf getting
the gene from a mating of two carrier parents should be 25%. If both parents are
carriers, there should also be a 50% chance of getting a "carrier" calf, and a 25%
chance of getting a non-carrier or homozygous normal calf. From a mating of carrier
and non-carrier, the statistical probability is supposed to be 50% for a calf of either
of those types (no chance for bulldog). From a mating of two non-carriers, the only
result is a non-carrier.
If this is clear enough, the buyer should be able to choose his/her own goals. Many
breeds have made a concerted effort to rid themselves of genetic anomalies. In the
case of Dexters, a minor if not rare breed, breeders and associations must decide
whether the gene pool will be more helped or hurt by efforts to do such at this time;
and individual breeders may decide whether the chondro gene appears to have any value
for survival or temperament or aesthetics or market or any number of things. Custodians
of a rare breed must be especially careful not to burn bridges and to take a long view
for the betterment of the breed, and even new breeders will do well to look beyond their
pocketbooks to the survival of the breed as a whole. Good, conscientious breeders are
of mixed opinion on this at this time.
What about PHA?
Like chondrodysplasia,P HA is a genetic issue, not contagious, and not a disease. Pulmonary
Hypoplasia with Anasarca. A fetus becomes a dead “waterbaby” and may be undeliverable except by
Caesarean section. The DNA test for this gene allows the owner to know which animals carry it and
which don't and make it manageable. The Dexters which do not have the gene at all are non-carriers
of PHA or "normal" in relation to that gene.
The "waterbaby" non-viable fetus results from the calf inheriting this PHA gene from BOTH parents.
The statistical probability of a calf getting the gene from a mating of two carrier parents should be 25%.
If both parents are carriers, there should also be a 50% chance of getting a "carrier" calf, and a 25%
chance of getting a non-carrier or homozygous normal calf. From a mating of carrier and non-carrier,
the statistical probability is supposed to be 50% for a calf of either of those types (no chance for
fetus dead from PHA). From a mating of two non-carriers, the only result is a non-carrier.
If this is clear enough, the buyer should be able to choose his/her own goals here too. While on surface
an immediate effort to rid the breed of any genetic anomalies might seem like a wise course, I do not
believe it is either necessary or prudent to rush into this with “deadly weapons.” I myself would
recommend avoiding risks of potential vet costs or loss of dam from a waterbaby fetus by never breeding
carrier to carrier. However, the only problem with breeding carrier to non-carrier, with a resultant
carrier calf risk of 50% (remembering that “normal” non-carrier birth is also 50% chance), is the cost
of testing so that a breeder can do a responsible job of breeding and selling. For someone with a herd
of 20 cows with the gene present, that testing becomes a significant issue. But for a new breeder with,
say, six cows, the cost can be as little as $120 per year for testing (assuming that a year’s calf crop
is of all calves s/he would want to keep in the herd or sell—which in itself is unlikely). Meanwhile,
the likelihood of getting some non-carriers is strong. Much of the time a calf crop will include too many
males to use or sell, and some will be chosen for meat or showsteer/oxen prospects anyway. No problem with
PHA-carriers there. Nearly all sellers would reduce the price of their PHA-carrier animals, so in pure
economics, a new breeder would probably be ahead to buy them. The new breeder could then eat the
carrier-calves or use them judiciously (with testing of their offspring) and manage the problem responsibly
and gradually. Custodians of a rare or minor breed must be especially mindful to care for the gene pool and
to take a long view for the betterment of the breed. Good, conscientious breeders can and do MANAGE their herds.
What about Horns?
First a word about the terms: "Horned" and "dehorned" cattle are genetically horned
animals; "dehorned" means that the horns have been mechanically/chemically removed. "Polled"
cattle are genetically and naturally hornless. Scurs are smallish, hornlike projections
or horny scabs, and only show up on polled animals. Recognizing the differences is not
always easy, so understanding the terms can be very helpful when you are talking with a
potential seller and asking questions.
My individual ideas on the subject of whether or not horns are desirable/tolerable on
cattle have changed. I began with a perspective coming from a beef background. Horns
are a nuisance if you have many animals crowded together in any situation, and dehorning
is not fun. So I wanted polled. In trying to foster a calf on a "pasture" mother, I
discovered the value of horns for tying without the mother "choking down." I left horns
on a bunch of calves to give enough time to be sure that polled were correctly registered
and I began to be able to interact with horned animals, which gave me no more trouble
than dehorned or polled ones in the forage-based system I use. So now I am not adamant
about liking any of the three conditions more than another. Some people like horned
because they are part of the traditional look of Dexters or because they think they are
attractive. Some dislike polled because they think they are less pure Dexter. Much of
Dexter history is buried so deeply in the past that that particular point may possibly
be solved when DNA analysis becomes more sophisticated, but now is only relevant as far
as integrity of breeders and breed associations go in appropriately registering animals
to the correct parents. Both ADCA and PDCA recognize polled Dexters as "real" Dexters
if they come through established parental lines. So it is a matter of breeder and buyer
Regarding dehorning, before I began leaving horns on my Dexters, I successfully used the
caustic paste dehorner. It seemed to give the calf little discomfort and the results were
perfect. I followed the directions very carefully. Some breeders recommend using a
heat-based dehorning wand. The success of both these methods is heavily influenced by
the age of the animal. For adult cows, the ONLY method I would recommend if you absolutely
must do it is the Tri-Bander. A bull's horns are bigger at the base even earlier in his
life so I would not want to sell someone one of my horned Dexter bulls to be dehorned. In
my earliest Dexter purchases I took a cow to the vet for dehorning and I never wish to
have that done to one of my animals again. So if you don't want horns, buy polled, ask
the breeder to dehorn early for you, or, some would say, choose a different breed.
If you as a breeder ever discover a polled Dexter calf from horned (or dehorned) Dexter
parents, PLEASE report it to your chosen association and have calf and both parents
DNA-tested. I am hoping to have such a calf, just as I am hoping to have twins some day!
Are Dexters miniature cattle?
Dexters are not MINIATURIZED cattle bred down from a larger breed, as Dexters have been
small from the first records of their existence. By the definition of "miniature" as
any bovine under a frame score of 1, then many Dexters qualify. Frame score charts often
have age and hip height axes. Three-year-old cows of 42 inches and under and bulls of 44
inches and under at hip measurement meet that qualification for the term "miniature." For
some reason, the word is a "hot button" but the reason is probably because of our pride
that the Dexter is not a miniaturized version of an "improved" breed but rather a fairly
rare and special and "primitive" breed. Sometimes overlooked are the minimums mentioned
in the guidelines of 36 inches for a cow of three and 38 for a bull of three. These
"desired height ranges" between the lower and upper numbers correspond roughly with frame
scores from 0000 to 0 in both sexes.
What about the "standard"? What about color?
Some breeds and species have a "breed standard" and prohibit registration (or strongly
recommend non-registration) of purebred animals which do not fit the standard. In contrast,
the Dexter breed has GUIDELINES. Before the printed Guidelines in an official Dexter
publication of 2004 (when there was one Dexter association in the U.S.) are these words:
"The following guidelines for the Dexter bull/cow are meant as a guide to Dexter enthusiasts
and breeders, and represent ADCA consensus as to desired characteristics. These guidelines
are not used to determine the registration of animals, which is solely a matter of pedigree."
The framers of the guidelines carefully distinguished the official guidelines from the
kind of standard mentioned at the opening of the paragraph. Breeders of Dexters are trusted
to use their common sense, and to work for the well-being of the breed. In the ethos of
yesteryear in America, that was seemingly enough, much of the time, and those who kept
Dexters had a pride in the good breeding of their "little cattle." If an outstanding bull
was 45 inches instead of 44 there was no prohibition against using him, but presumably
breeders would try to use him on smaller cows to stick to the general consensus of desired
characteristics in getting desired-size offspring. Since the chondrodysplasia test had not
been devised yet, this could mean that non-carrier offspring of carrier cows would be rather
large in such a case, but the consensus remained and breeders aimed for some consistency.
Today there is no prohibition against using a 45 inch (at 3 years) bull, but arguments
continue about height (both regarding maximum and minimum and regarding having separate
guidelines for carriers and non-carriers). I do not, personally, desire a change in the
guidelines because they are clearly a desirable but not compulsory set of ideas regarding
what breeders will want to aim for.
White on the rear underline was not prohibited nor even reported on registrations in
earlier years. Much less were outstanding specimens turned into meat animals because
of a little white. The white may indicate some of the earlier, perhaps founding, genes
in a strain of cattle, so that is of interest. Breeder integrity in registering pure
animals is important in registered stock. But Dexter origins are shrouded in mystery
so the signs to help us decipher the riddle should not merely be removed or covered
up. However, the CONSENSUS when the guidelines were formulated was that Dexters were
ideally to be of "whole" color with only a few places on the body with white really
accepted. Rarely is color of protective or harming value to today’s cattle in the U.S.,
so my opinion is that the color issue in the guidelines is of far less importance than
the conformation issues which have to do with the animals’ structure, and thus long
term health and ability to function well. I do color tests because they are now required
for proper registration, but otherwise would not. That color is now a market issue merely
marks the fads that humans enjoy when something is rarer than something else. Probably
harmless but unimportant. (This is arguable since colors reflect heat and light differently
and some colors may have more value in some areas of the world and Dexters ARE an
international breed...but in general in temperate climates, color may be one of the less
important qualities... )