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GDC EXCHANGE: In the U.K. you publish hip
and elbow evaluations openly, and provide that data on a sire's progeny so that breeders
can make decisions based on the quality of his puppies. How does that work?
Dr. Willis: In the UK and in other European
countries there are evaluation schemes, usually run by the kennel club, a veterinary
group and/or breed clubs. In Britain the British Veterinary Association/Kennel Club hip
scoring scheme allows any dog aged 12 months or more to have its hips "scored." Scoring
involves eight radiographic features on a scale of zero to six and one on a scale of zero
to five so that a dog can score from 0/0 (ideal) to 53/53 (worst). The worst breed average
is the Cumber spaniel at about 42, and the best is the Siberian Husky at about six. A
similar scheme exists for testing elbows (scale 0-3) and also for testing for various eye
diseases, but I am involved officially only in the hip scheme.
We publish sire figures, and, when a breed asks me, I
publish records of what is happening in the breed. As soon as a dog through our scheme has
ten progeny that we have scored, we publish data showing: (1) how many progeny he got; (2)
how many mothers they were out of (the more the better); (3) what the best and worst progeny
were; (4) the mean progeny score and how the scores were distributed in the progeny.
When I've got a dog I'm interested in, I would look at
siblings, and I would get as many of them scored as possible. But once I start having enough
progeny, I can throw away the siblings, I can throw away the dog's own score, and I can
throw away the pedigree. If the progeny are poor, end of story. If they are good, carry on.
I find a lot of good-hipped dogs who produce poor progeny, but I have never yet found a
bad-hipped dog whose progeny record was wonderful. In other words if the dog is bad, stop
using him now.
If we take a breed like Newfoundlands, for example, in
the last 20 years they've made an improvement of about 0.73 points per year. Now that
may not seem like a lot, but it means they've gone down from an average score of 37 to an
average score of 22. When we publish sire data in that breed we have some who are producing
mean hip scores for their progeny of around 8 compared with the breed average in the 20s.
And we have also sires who are producing averages of around 43.
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GDC EXCHANGE: So a sire who is producing poor
quality hips in progeny will be known to everybody?
Dr. Willis: That's how it works. Peer pressure
forces many breeders to hip score and take note of the results. And there is no question
that once I publish those progeny data, the stud careers of some of these dogs are markedly
affected. And there's not much a stud owner can do about it. Because even if he stops
sending his own results in, he cannot stop people who've used his dog from sending in
their results.
Now for example, one top winning German Shepherd has a
hip score of 13 which is better than breed average. But the average in his progeny is
30-something. As soon as that became obvious, his stud career has gone down the tube. Now,
he's still being used, because people say "I don't give a damn, such a lovely dog, I'm
going to use him anyway." But he isn't getting used like he would have been if he were
producing good hips.
Of course, you've got to weigh hip and elbow status
alongside the other merits of the dog. A Bernese Mtn. Dog with excellent hips and elbows
but with a very poor character may not be worth using for breeding. In contrast, a dog with
less than excellent hips, but with outstanding merit and character may be worth using if
mated to a carefully chosen mate.
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GDC EXCHANGE: Your book, "Genetics of the
Dog," seems to be on the must-read list of many responsible breeders. So, in addition
to buying your book, what does a person need to know to become a good dog breeder?
Dr. Willis: In my view, the first need is to know
history. If one does not know history one is forced to repeat it. Read all you can on your
breed. That will include some books that are rubbish and some that are good. You have to learn
to sort wheat from chaff, and you also have to start to put facts and figures to dogs. Breed
surveys , if you're lucky enough to find one that has been done on your breed, are also a very
valuable source of information.
Then you have to start putting flesh on the names in your
dog's pedigree or in the pedigrees of dogs you are seeing at shows and other events . You
need to go to events and sit at the feet of some expert (if you can find one) to learn about
the breed as it is. Going to a show is not enough if you spend it in the bar or just watching
dogs go around without seeing what makes one better than another.
Ask questions and listen to answers, trying always to sort
the relevant from the useless. Do not become hidebound by specific ideas; question
everything, even what I'm saying and what I write in my books. Think about everything,
digest it, discuss it and ask more questions. Always try to learn and advance your
understanding of the breed.
More than anything, what breeders have to do is breed
for themselves and to further the breed in general. They should only breed a litter when
they want to carry on the line, and not because they need to update their car, etc. And
from that first litter forward, a breeder also has to keep complete records on his dogs,
and make contracts with his puppy buyers so that he will look after the dogs he brings
into the world. A breeder who has no interest in rescue of what he has produced is of no
value to anyone, and of even less value to his breed.
As a responsible breeder you need to work with others, you
need to collaborate towards the same ideal, so that the number of good quality breeding
animals is increased. You also have an obligation to learn as much as possible about the
genetics of animal breeding because that is what you are going to indulge in. You need to
know basic genetics because you must put your dogs through the necessary schemes (screening
and evaluation of hips/eyes/elbows, etc.) as appropriate.
Breeders need to understand how to select for simple
recessive (single gene) traits and polygenic traits like hip dysplasia. They also need
to understand the concept of heritability. With polygenic traits, if the heritability is
very low (litter size, for example, has low heritability), then little progress results
from direct selection because the performance of an individual is not a good guide to his
breeding merit. With high heritabilities (hip dysplasia has a relatively high heritability),
progress is better because the animal's performance is a good guide to breeding merit.
Even so, you must not breed only by the numbers. A good
breeder goes about the job with a set aim of trying to produce functional dogs that
approximate to the ideal. I see breeders who cannot see beyond a head or a light eye or a
good set of hips. Such breeders are doomed to failure because they do not look at the
whole dog.
And you've always got to try to select stock that is
not only much better than the breed average, but much better than your kennel average. If
you breed from parents that are better than average, their progeny will be better than
average, but not, on average, as good as their parents. If you breed from parents that are
worse than average, their progeny will also be worse than average, but not, on average, as
poor as the parents. There is, in effect, a pull towards the mean. And that's why it can be
so hard to improve the breed.
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Finally, all breeders will produce defects if they breed
long enough. Those who tell you that they do not produce defects have either stopped
breeding, breed hardly at all or are being economical with the truth. There is no crime
in producing a defect. The crime, if any, lies in what you do about a defect. If you bury
yours quickly and keep quiet about it, and I do the same with mine, then sooner or later
we may use each other's dogs and pay the penalty for not having been honest with one
another and with the breed we probably profess to love.
In simple terms, breeding is all about selecting the
best and then mating the best to the best. "Best" is a relative term and to a great
many breeders best is what they happen to own. Sometimes they are correct in that assumption
but more often than not they are wrong because they are not critical enough of their own stock.
You have to distinguish clearly between the pick of the
litter and the best breeding material. Many breeders are quite capable of deciding which
is the best puppy in a litter. Things can certainly go wrong with hips, mouths or other
features between 8 weeks and adulthood but nonetheless pick of the litter is not very
difficult to find given some experience of the breed and the bloodlines. The difficulty
is in deciding whether pick of litter is an outstanding dog in breed terms. The pick in
a litter may be little more than an ordinary dog when assessed against the breed standard.
Breeding, if it is to be successful, requires the breeder to be able to distinguish between
ordinary dogs and outstanding ones and, ideally, to be able to do this quite early in the
dog's life.
Mating dogs is not dog breeding. It is the reproduction
of dogs. A breeder should be seeking to mate the right dogs in the right way so that he
produces the ideal (or as near to it as possible) in his kennels. That is only feasible
if the breeder knows what the ideal is. |