|
BREED VALUE
and the GSD - The SV Zuchtwert Program |
|
. |
Many GSD fanciers (yes,
unfortunately even breeders) have either not heard of the Zuchtwert
program or have almost no idea of what it is. For nearly four decades, the
world of dogs has known about canine hip dysplasia
(HD) and has followed protocols laid down in the 1950s and ‘60s for diagnosis
and control. In the U.S., pedigree registration has been taken over by AKC,
UKC, and other organizations while the primary focus on dysplasia
has been on and by the OFA; in Europe and elsewhere, the breed clubs have the
responsibility for both registration and disease control. In both, the
methodology of diagnosis had been basically the same: a ventrodorsal
radiographic view with the dog’s legs stretched out straight. This has proven
to be of great value in detecting DJD, degenerative joint disease, but only of
limited usefulness in discovering joint laxity (the primary precursor to DJD,
and another definition for HD). Since dog breeders and buyers have become
dissatisfied with the lack of suitable progress, we have looked for some
advance that would enable us to rise above this plateau we have reached with
the old methods.
In
In its general meeting in May
1998 in
Individual animals do not always
reproduce themselves as we often hope. It is common experience in the breed scene, that some show winner, performance star, or other
champion or typey dog produces disappointingly, while
on the other hand, an almost dreamlike ideal, normal, “to-the-standard” dog
often results from an accidental breeding. Similarly, one must understand that
a healthy dog gives no guarantee that his progeny will be healthy. HD, elbow dysplasia,
epilepsy, eye disorders, etc. unexpectedly arise from apparently normal
parents, and catch most breeders unawares. Then if characteristics can be
different in the breeding animal than in its progeny, one must wonder why have all these breed surveys and breeding requirements? And how can we set it up so that the
phenotypes of those animals can tell us how they will probably produce?
Each breeder tries to include
already-available information concerning siblings and his own experience with
other progeny. No breeder can put forward a really objective picture, however.
Additionally, there is the tremendous abundance of dogs in the breed, and no
one is in the position of getting and cataloging
their achievement tests or health control data, not with well over 30,000
puppies born annually. So up to now all we could do was consider
only the stud dogs or the breeding bitches themselves. Today, however, the time is ripe for more. Computer technology and
the information revolution have matured so that the club (SV) can document not
only all members, but also can give clues regarding how good
the dogs themselves should be, and how they will probably produce.
Definition of the Breed
Value
Breed Value Assessment (Zuchtwert) is the attempt to describe how an animal will
pass characteristics to its progeny. Hereditary transmission (whether improving
or weakening) is described to breeders as “value or breed worthiness”, and is
expressed in the form of a number. An animal bequeathing an “average” value
(neither improving nor worsening) has a value of 100. Animals that improve upon
this average in the breeding scheme (in HD that would be lowering the incidence
in progeny) are given value numbers under 100; animals that magnify or
increase the feature will have values over 100. With this system, the breeder
need no longer focus [as much?] on whether a particular dog is free of HD, or
what degree of laxity/tightness it has; in the future he can expect a reduced
risk of HD (smaller ZW number) or an increased risk (high number).
We thus have numbers that tell
us what the animals’ phenotypes or performances are like. For instance, the score
earned in tracking work tells us whether the dog was good or bad. We have
numbers about the size (shoulder height), and points on gait or type. In many
features there is a numerical value, which tells us how
pronounced the characteristic is. As breeders, however, we need a number that
tells us how pronounced the feature in the progeny will likely be. In other
words, use phenotype and progeny testing to give a better clue as to genotype.
This number, to be applied to the breed, is called Zuchtwert
(breed value). There is therefore, for
each feature, one phenotypic measurement and one genetic breed value. As
concerns HD, (unquestionably the most urgent ZW trait considered by the SV) a
breed value is to be published from now on for each dog. The fight against hip dysplasia is of great concern in the German Shepherd Dog. As the world’s most populous breed, its name
is brought up again and again in connection with hereditary diseases and breed
faults. One may lament that as being unjust, because in other, smaller-population
breeds there are much higher percentages though the absolute numbers are less
conspicuous. However, whining complaints and rationalizations are of little
use. There is an old maxim: the larger and more striking a picture of oneself
that one presents to the public, so much better must he actually be!
With this explanation, the
definition of the breed value becomes understandable: it is a numerical value
to be applied to the breed to describe the effects that the genes have on a
trait, compared to the genes of the rest of the population and the effects of
normal environments. We must emphasize first of all that the breed value has
nothing to do with how valuable or worthless an individual dog is, but is only
a numerical value describing if the genes working on this trait strengthen
(improve) or weaken it for the next generation. For diseases, that means that
high breed value numbers indicate a worsening of what the breeders see as
undesirable re the disease or anatomical construction. The goal must be to
introduce breeding animals that reduce the disease risk in the breed. Low
numbers are therefore more valuable in such cases! With other traits, such as
outstanding predisposition for high drives, we would take high ZW numbers as
being prized or desirable. With height at withers, it is not that simple. A
high breed value for a dog in this instance means that his genes increase the
size. That can be valuable and important for a small bitch. For a bitch already
over the limit, such a dog is not recommended. It is up to the breeder to use
his best judgment to select the suitable dogs for his bitch, and it is best if
he first knows what the breed values are.
The Relative Breed
Value
If one is to advertise or
publish breed values, they must be easily understood. An HD breed value of
+0.14 means for example, that with an equivalently-rated partner, the offspring
probably will be 0.14 (HD degrees or points) higher. This is unwieldy;
therefore, breed values are not expressed as absolute numbers, but as relative
to the breed cross-section. Therefore we take 100 (points) for the breed level
(as typical or average). Dogs with ZW over 100 increase
(worsen), while those under 100 reduce, the characteristic. A technical
point, but to be stated despite my recommendation to forget about it right
away, is that the variation from the median amounts to 10 points either way;
this means that a reported ZW of 90 should be read as a range of 80 to
100. Thus, if a bitch has a breed value
of 95 for HD, one knows that she can improve the breed, but a dog with ZW of
115 exacerbates the HD problems. By referring to breed averages, the
classifications regarding different characteristics also become comparable. If
we get, for example, a dog with HD 92 and shoulder height 108, this makes it
clear that he is a breeding partner that can be used for improving the HD
scores and increasing the inherited size trait.
Why is Breed Value
Median Always Only an Estimate?
One finds, in the biology of
inheritance, that we can determine the true breed value only with
difficulty. The owner's personal,
subjective judgment of his animals is not a 100-percent reflection of the
genes; therefore we recommend the use of breed values. The ZW number is not a
mathematically precise guarantee of genetic constitution because:
1. The genes work only in the particular individuals themselves and
not in concert with the genes in the rest of the population (there can be, for
example, action of concealed recessive genes that do not show in others).
2. Environment certainly influences the expression of the genes in
these animals.
Both reasons (for ZW being only
an estimate) give a false picture. The reliability with which one can recognize
the true breed value from the appearance (phenotype) is, for instance, around
20% for HD, for shoulder height around 50%, etc. One calls this percentage
heredity and/or heritability. [Note: Such heritability figures are not always
backed up with scientific studies and professional, peer-reviewed journal
articles. For example, OFA has given 0.25 as the heritability of HD but has
never produced any evidence to back this up.
Meanwhile, organizations such as the University of Pennsylvania and The
Seeing Eye, Inc. have concluded with reasonable reliability that the PennHIP diagnostic technique gives a heritability figure of
over 0.4, meaning that their method is considerably more “telling” than the
leg-extended views used by SV, OFA, GDC, etc. Heritability varies with breed,
diagnostic technique, even a person’s own strain of bloodlines.]
Each animal receives his genes
from father and mother, half from each one at random. Information about
siblings or progeny is thus based only on a random
gene sampling from the contribution of the parents. First, the statistics allow
us to get an approximate picture from abundant knowledge and/or
observations. A spoonful from the stock
pot gives only a chance picture as to how many "chunks" and how much
"broth" are in the stew, and each additional ladle shows us more
accurately how rich the soup is. So also our knowledge about the genetic
"capacity" of a breeding animal increases with each additional litter
he or she produces.
Present Standing of the
Knowledge
Breed values help decide many
things: whether to use a stud dog for a given bitch, a breed survey, a puppy
sale, if the puppy should become a breed dog, and yes, even before birth, since
the question is put as to whether subsequent puppies are themselves programmed
for life by their genetic portion. All available information must be used to bring
us to the knowledge needed to make an estimated breed value (ZW). Estimated
breed value means “the most probable genetic production, as determined by the
current knowledge”. Since in the course
of time more knowledge is always forthcoming, certain limitations of the ZW
estimates will also change. Several have
made comments such as, “It is not clear how the SV arrives at the ZW-HD
numbers. Until we know that, the ratings are less valuable than they should be,
despite SV regulations.” Certainly,
there is a need for the SV to do more about the limitations of the system and
its interpretation, but it is still a big step forward; there is also a need
for breeders to support such programs. Dr. Beuing
presents the picture of this need as consisting of half a dozen or so “levels
of knowledge”.
First
level of knowledge
From father and mother ZW
estimates, we can make some statements about what genetic contributions may
exist. Since father and mother each bring in half of the genes in each of the
puppies, and the effect of these genes is described by the breed value, then
for the calculating of ZWs of the puppies, it must be
1/2 the sire’s breed value plus 1/2 the dam's breed value. This is the same as
saying you can add the ZWs of sire and dam and take
the average (divide by 2) to give the starting ZW for your dog. Once a dog gets
out of
Second
level of knowledge
While one can learn the ZW even
before the actual mating, dogs can also be evaluated and “scored” by using data
on earlier litters of these parents. These siblings can improve the evidence
about father or mother and their “progeny-correcting” breed values. Breed
values for individual puppies thus can be known somewhat, without physically
evaluating the puppies themselves.
Third
level of knowledge
At the beginning, the level of
knowledge was derived only from the breed values of the parents, which with
time and more progeny become increasingly more accurate. Since all puppies of a
litter have the same parents, all puppies must also begin with equal estimated
breed values. Each puppy however has received respectively half from the
father’s and half from the mother’s genomes. By sheer good fortune, a puppy
thus can have received more favorable genes than have
his littermates. This “distribution of good luck” or “distribution of bad luck”
at the stage of cell combination and development of the egg and sperm leads to
the fact that full siblings can considerably differ genetically [as well as phenotypically] in their particulars. Whether an individual
animal is blest or cursed by the random allocation, for instance in reference
to the HD genes, can be estimated only if the animals are radiographed
for HD. The picture depends on “egg & sperm contribution” but also on
environmental factors, radiographic technique, position, and subjective
judgment.
Fourth
level of knowledge
If full siblings also get
evaluated, and especially if most are assessed quite close to the time that the
animal of interest (called the “proband” or
“probationer”) is under consideration, then their “declarations” supplement the
breed values of the parents and also indirectly the breed value of the
“probationer” (your dog, for example). Breed values thus can change further
after individual appraisals, even if a dog is never used in the breed.
Fifth
level of knowledge
If the animal does come into the
breed’s gene pool, his genetic continuity becomes effective in his progeny,
combined with different breeding partners. With each examined offspring, the
knowledge climbs in importance beyond his own former
ZW. The estimated values themselves vary from the average of the [original]
breed value. With each puppy whelped, points begin again for another first
level of knowledge, so that the breeder comes full circle and starts all over
again with each litter.
Further
knowledge
If a descendant is evaluated, he
gives knowledge about father and mother. The father will bring such information
to the descendant that is not clearly provided by the mother, and the mother
contributes only that which is not donated by the father. The following simple
situation should serve as example:
I import a dog and a bitch;
nothing is known about their relatives. A litter from these reveals bad HD
results. Since the placing of blame on only one parent is not possible, both
receive uniformly and equally a bad breed value (e.g., 110). The bitch whelps a
second litter sired by a frequently used stud dog with a ZW of 89 (he already
has 80 offspring, 30 of them radiographed, with
predominantly good hips) and we find again that she produces medium and severe
HD. Now, the transmission of many bad genes by the bitch becomes evident
through this second pairing, because with a known good-producing dog she has
undesirable results! Her breed value index drastically rises thereby. And that
has consequences for further use of the imported stud dog that was the sire of
the first litter. He is exonerated, and can possibly get 100 or under, even if
he personally has no further progeny.
The
claim
Breed Value Assessment (Zuchtwertschätzung) does not claim to document the truth
about the “genes”. But it should give indication of the presence of good or unfavorable genes. The breeder urgently needs these signs.
He must build his kennel with the foundation of genes from the best families,
and take all indications of problems under consideration, be they HD, size,
character, working ability, etc. When breed clubs offer instruction through
this Zuchtwert assessment, at least for some feature
urgently in need of attention in the beginning, the breed will develop quickly
in the desired direction. Since 1989, Zuchtwertschätzung
has been used in other clubs, with subsequently developed breeding programs,
but also for non-binding information.
ZW Mandatory As Of July 1999
Wide implementation of the
method of Breed Value Assessment has been effective in the “commercial animal”
breeds (food & textile). This includes, in a computer record, all available
data of the ancestors and any available progeny as well as of the personal
phenotype of the animal concerned, and can work authentically and exceedingly
effectively in the purebred dog. In cooperation with the Institute for Breeding
Animals and Animal Genetics at the University of Gießen,
the SV developed a breeding program that became obligatory as of July 1, 1999.
Before that, starting in September 1998, the process was voluntary. Each
breeder currently and henceforth knows about the inheritance (HD-production) risk
of his bitch through this HD breed value. The breed value numbers of all stud
dogs are likewise disclosed. From both of these sides comes a greater knowledge
of HD risk for their progeny. The official position of the SV is that
considerable breeding progress in the area of declining HD incidence can be had
by implementing this measure.
The HD Program of the
SV
Success speaks for itself. The
SV has had a protocol for HD control since 1966, which was recognized at an
international technical convention in l974 as "the best in the
world." Nothing has changed about it until recently.
Through mid-1999, over 260,000 German Shepherd Dogs had been
X-rayed in the SV’s HD scheme, and about 240,000 dogs
received that coveted "a" stamp, which denotes official permission
for the dog to be bred. Approximately 13,000 new "a" stamps are
awarded annually. The percentage of dogs with medium and severe HD was
drastically reduced by initially 27%, until today there are only around 6% as
identified in the old diagnostic technique.
The SV has indeed made greater strides in lowering the number of
severe-HD cases and preventing severely dysplastic
dogs from breeding, than have
Decisively involved with the
success of the battle in
****************************************************************************
Dr. Beuing, the administrator of the ZW project for the SV,
answers the following most frequent questions on the SV website and mailings to
certain members. However, he does not really answer satisfactorily, partly
because geneticists use such complicated formulas for BV. My
(Fred’s) comments in brackets.
1. How is the Breed Value HD worked out for my dog? What is the
formula for it?
There is no precise formula in
these calculations. The ZW of every animal [whose parents
were not already calculated] was considered “unknown"
at the beginning of the calculations. Then an equation is put up for every
animal, with the formula:
(ZW for HD) = the
breed average + Breed Value of this animal + variation of sex + other
influences.
In this equation the breed average, breed value and the effect of
the sex are formulated as the "cause" of HD. In the SV, 450,000
equations were formulated for 450,000 animals, with the 450,000 unknown Breed
Values. Then some supplementary conditions (stipulations or prerequisites) of
the laws of inheritance and heredity are mathematically formulated. Following
this, the computer has to solve the 450,000 equations with the 450,000 unknown
factors. The answers are the assessed (estimated) Breed Values. This means that
there is no formula, in which a dog's breed value is worked out on its own.
2. What role does its own HD score play in my dog's HD Breed Value?
The dog's
own HD grade modifies that which was already known about the sire and dam.
Siblings may differ because of their own HD status. If an animal has progeny,
its own HD status [“a”-stamp grade] recedes more and more into the background,
becomes less of a factor. With 30 - 40 progeny, it is practically of no
consequence. [We see here that the ZW program
uses that old reliable “progeny testing” approach, which makes it far better
than what we use in the U.S. Hinted in Beuing’s
answer here is the tacit acknowledgement that the “a”-stamp for hips is not all
that reliable, something he dares not say unequivocally. Even though the “
3. How is a foreign “a” [or equivalent] evaluated for the ZW Breed
Value Assessment?
At this time, dogs from abroad
with the “a”, OFA, etc. are evaluated in the formulations as though they were
not X-rayed. Their ZW is gained only through their X-rayed relatives. As these
foreign animals cannot be clearly termed as “HD-free” or “still acceptable” [noch zugelassen], an assumption in this case, would be unfair.
4. How can a dog that was not X-rayed have a ZW for HD?
In the system of equations (see
Answer 1), there is a lateral clause, that the father and the mother each
contribute half of their genes to the progeny. Therefore the Breed Value of the
progeny can be assessed or estimated, if nothing is known about the animal (not
X-rayed), as well as if the breed value of the sire and dam are known. In the
same way, a parent can be assessed if the progeny is known, because progeny
have one half of their genes from each parent. Siblings on the one hand help to
characterize the parents, the knowledge about the
breed value of the parents helps on the other hand, to assess the breed value
of the untested siblings.
5. How accurate can the Breed Value Assessment be, if no HD
information is available for more than half of the whelps?
In the ZW Estimate, the percentage
of the pups does not matter, but the total number. The last Sieger
has his heritage well demonstrated by 71 X-rayed progeny as of early 1999. [Each month I get
from the SV the news of breedings by German dogs, and
can watch the ZW numbers change. Sieger Rikkor, mentioned here, had as high as 118, meaning that he
has produced an uncomfortably high number of dysplastic
dogs. As his owner requires (or is limited to) lower ZW numbers on prospective
partners, his own ZW slowly comes down a little. This has been seen in the past
year and more, with a ZW of about 110 as of mid-2000. The ZW of an unproven dog
is an average of both parents, and the “requirement” now is that this average
must not exceed 100 (the breed “average”); that such a mating will not be
allowed/registered. However, even though the SV says that, they allow
plenty of exceptions, as the monthly stud service/litter announcement
publication shows.]
6. My bitch has passed on [the ability to
get] the “a”-stamp well up to now. What happens if I
mate her to a dog that has a HD Breed Value over 100?
If the bitch has produced well,
this must be seen in her ZW. Good progeny, however, can also be the result of
good matings. If the bitch, for instance, is mated to
a dog with a value of 100 [or higher], then the risk for the
puppies is higher. The bitch is only “accredited negatively” if the pups are
worse than could be expected with that stud dog. Generally it might well be
that the stud dog owner would want to accept “poor” bitches, because that way
his dog can show plainly that he “improves”. [(in
regard to hips) Unfortunately, this is not the best way to improve the breed as
a whole, and can be considered a very selfish and deceptive tactic, as well as
very risky, because more people will look at his ZW than calculate how much
better the progeny’s hips are than their dams’ were]. With HD, where there is no better rating than “HD-free”, it
is difficult to prove a positive heritability of the top bitches.
7. How do dogs that have no HD findings flow into the HD ZW
calculations?
At this stage, non-radiographed animals are “neutral” for the ZW; they are not
taken into consideration.
8. What does the mean Breed Value of 100,
and the stated deviation of the standard of ten points mentioned in the
breeding plan mean?
The ZW of 100 means that the
animal's hip heredity is typical or average for the breed. At this time the breed mean is 1.71 (that is, between HD-free and
mild HD). What is passed on can be better or worse than 100. The average
deviation above or below this mean will be set at 10 points.
9. What does a hip Breed Value higher than 100 mean for my dog?
This ZW for such a dog means
that he passes on poorly [in regard to
sound hips]. As
the breed average itself is still unsatisfactory, matings should be striven for that bring the average under 100. Still, “you must not throw
out the baby with the bath water.” The first priorities are working ability,
temperament, and so on. If one finds a stud dog who
brings the expectations for the pups (the average of father and mother) below
the 100 value, that is sufficient.
10. Conversely, what does a breed value below 100 mean for my dog?
A ZW below 100 means that there
is a greater freedom in the choice of dogs [to
breed with] who are firm in character, strong
in performance, and of good body construction, even if their breed value is around 100. With a bitch value of 83, one can
even accept breeding to a dog of 117!
11. Can a Breed Value be worked out for criteria other than HD and,
if so, for which ones?
A ZW estimate can be obtained
for other characteristics. For this, it is important that the particular
characteristic is accurately defined.
Dr. Reiner Beuing, Institute for
Breeding Animals and Animal Genetics,
***************************************************************************************
Some Recommendations
for Breeders: The Next Step in Progress
Dr. Beuing
says: The most important aspect is that we care for the health of the dog. It
is also a question of humane animal protection: the animal protection law in
Oh, yes, objections will
immediately come up here! We should not base our selection only on what the
individuals themselves are like but, since it deals with the selection of
breeding animals, we must pay attention to how the animals produce. Therefore
it must also be possible to weed out from the breed some supposedly “HD-free”
individuals if they produce badly, and we must perhaps give good-producers from
good lines a chance, even if their own radiographic evaluations have shown HD
in a borderline or mild case. [Remember, there are inaccuracies in the standard view of hips.
Using the combination of low ZW numbers and the best diagnostic method, this
weeding and improving can be accomplished most rapidly.] The concept that is really new
and lacking from previous education in SV thinking is that now the inherited
traits, that is to say, the puppies’ quality, moves into the forefront. We
breeders should no longer concentrate on the individual breeding animal, but on
the pairing, the combination! Both partners in the breeding pair jointly
determine the hereditary factors (genes) in the puppies. [It is interesting to note, as I
did earlier, that the SV is trailing by many years the cattle industry and The
Seeing Eye, Inc., both of which have long been relying on Breed Value numbers
for guidance in such pairings.]
Comments on the
Individual Items
1. General
[The GSD is certainly not the
only breed in which hip dysplasia appears, but as
mentioned elsewhere, HD has a very high profile in the breed. A hereditary
predisposition is responsible for it. Therefore, measures were subsequently
formulated to serve the genetic improvement of the breed. In addition, the SV
continues to give advice for the breed’s suitable nourishment and necessary
care in infancy. According to the SV, scientific investigations have shown that
for HD, as diagnosed with the old leg-extended view, around 20% of the
(phenotype) variation from one animal
to another depends on differences in the genes. This low heritability shows
that other factors (in the individual) must also be considered, and therein lies the SV’s mistaken or undue
amount of emphasis on “upbringing”. Especially on optimized
nourishment and expert, cautious raising and training. Therefore they say that a breeding program
can be concerned with and solve only a part of the problem. Beyond that, it is
the duty of the SV, they say, to wage the HD fight via nourishment advice and
enlightened training and upbringing/maintenance practices.]
2. Determination of genetic risks
The SV employs an estimate, in
its attention to genes, by means of the Zuchtwert
evaluation. Presently the statistical process is determined by MMP and MME as
the best available procedure, which includes information on all relationships.
The breed worthiness is expressed as relative breed values with the median
value being 100 (representing a breed cross-section) and having a standard
deviation of 10 points. In the breeding program it must be determined how best
to make use of the Zuchtwert numbers and information.
Since it is a complex mathematical process, what is presented to the public is
only a summary of this scientifically studied and accepted method. The door is
left open for changing the process for a more effective one if it became
available. Presently, however, it is the technology of the Mixed Linear Models
that is the optimal process:
Ø
MME: Mixed Model Estimates for
the determination of any gross false clutter or interference with the
evaluation, and
Ø
MMP: Mixed Model Prediction for
the forecasting of the inherited transmission by the animals). The process some
perhaps know as “BLUP” belongs to this methodology.
3. Information
The HD classifications serve as
information for the Zuchtwert evaluation according to
the guidelines of the FCI. Further knowledge (from an earlier radiograph, for
example) is handled according to its relevance and importance. If one wants to
calculate breed worthiness from currently available information, it must be
regulated and defined just what information that would be. It should be clear
that current radiography remains unchanged at present. It was determined that
the current HD classifications [
4. Present calculation and information
responsibility
The current Zuchtwert
numbers are made available in a suitable manner at least at the beginning of
each quarter to members, breeders, and local clubs. In addition, the Zuchtwert is updated on “information-software” CD-ROMs (“SV
Genetics”), which are obtainable from the SV headquarters. These numbers are
required to be published in the mating-notice bulletins (Nachrichten des SV-Zuchtbuchamtes, — stud service or
mating news — etc.). In
5. Progress
Animals with medium and severe
HD have already been excluded from the gene pool — forbidden to breed —according to
Section 4, paragraph 1.3 of the breeding rules of the VDH. Nothing is lost if
animals that are themselves severely affected by HD are left with no potential
partners with far-enough below-average ZW numbers to breed to, anyhow… their
own Zuchtwert numbers are too high. Dogs that in regard to other features are
allowed to breed according to the Zuchtordnung (the
breeding rules of the SV), may be so included only in regard to their partners’
scores; which is to say, if the HD risk for the puppy itself as averaged from
the ZW numbers of the parents does not exceed a certain limit. At this time, a
limit of 100 is determined to be an upper boundary. It is recommended that you
strive for the lower values. The respective breed value published in the
quarter in which the date of mating falls, is the
figure that counts as the Zuchtwert of the breeding
pair. If the mating should occur within a maximum of 2 weeks after publication
of the Zuchtwert numbers, you could also use the
numbers given in the prior quarter as the bases for the average.
[Without such restrictions
and/or selection, no further progress could be expected. The peculiarity here,
however, lies in the distinctive form of the restrictions. To a certain extent,
it is contradictory to the idea of the master plan, if these breeding
restrictions were to be based on the owner's judgement of the animals and he
wanted to loosen them. However, the new rules now take effect. In the breed
scene the breeder now has the duty to look for such studs for his bitch who
prove to be the good genetic producers, those that are expected to produce
puppies with below-average risk. According to the SV, it is important that a
bitch remains in the gene pool as long as the breeder is successful in finding
dogs that are good enough for that bitch.]
Let us play through another
example: A bitch has a breed value (ZW) number of 102, i.e., she ranks slightly
higher than the medium risk. The breeder must be sure his first-choice dogs
(for performance, beauty, character, type, etc.) have ZWs
of 98 or lower. Let us assume he chooses a dog with the breed value of 96; then
the initial expectation for the puppies is 99, which is acceptable for the
breeding program. No one prevents him from taking her to perhaps “an 89 dog”.
Both studs are acceptable, but the conclusion is that the 98 is not as good as
the 89!
Now, a ZW assessment is no
guarantee. It certainly can happen that bad results can arise from this
combination. If the father already had many x-rayed progeny and one knows his
breed value with a high degree of confidence, this mostly affects the bitch.
Let us say her breed value amounts to 107 and that of the dog is 97 (average 102), so a repeat mating would be not
permitted. [However, I have already noted
that this “rule” is being circumvented all the time!] The breeder must choose for the next breeding a dog with a maximum
of 93 (average of 107 and 93 is 100). The breed progress regulations thus allow
for a range that permits much freedom in the choice of dogs, if the bitch
produces well. This always puts greater limits on choices, and forces the use
of good genetic producers, in proportion to how badly the bitch produces. Also,
in this standard range young animals from good producing lines have the best
chances. The principle of this Zuchtwert-oriented
breeding is called “strategic pairing”.
Now, there was still the problem
in the practical routine that after a cut-off date, breed values might have
lost their validity and new numbers put in their place. A mating planned and
arranged today could have become inadmissible tomorrow. In the discussion
leading to the establishment of this breeding scheme, this failing was revealed
and disarmed: in the first 14 days after validating a new Zuchtwert
figure, the numbers of the preceding quarter can also be put on the
application. If the new is better than the old, then the new of course is
valid. If the new number no longer meets the averaging requirements, but all is
arranged, the mating still is possible, insofar as the two-week time limit is
observed.
6. Matings in foreign
countries
Dogs from the foreign countries are
welcomed and may be used only if:
Ø
they are found in the database
of the SV with at least 3 generations,
Ø
an HD evaluation comparable with
the German method exists, and
Ø
a calculated breed value was used in the breeding.
Proof of the "a"-stamp
for HD was also necessary. In the passage of the new breeding program, it was
anticipated that the owners of dogs certified in the foreign country may get a
similar registration by applying to the SV and submitting the HD evaluation result.
After that first step, it is put "into the German market". If the dog
is initially integrated into the EDP of the SV, and the SV has a studbook (SZ)
number for him, then he is automatically included in the breed value procedure.
His progeny in
Experience and History
with ZW
The current expressions of
opinion are generally positive in outlook, supported substantially by two basic
principles:
- The application is very
simple for the breeder. For his bitch, whose HD breed value he knows, the
breeder can select from a broad offering of dogs that are qualified to
breed — suitable stud dogs that also complement his wishes in reference to
form and performance.
- The breeding program is
formulated comprehensively and unmistakably. Otherwise-suitable puppies
under 100, (therefore with below-average HD risk), should be bred.
This most modern Breed Value Assessment of the dog
undertaking the inclusion of all relatives was begun in 1983 for HD in the
German Spaniel. Later, German Jagdterriers followed
with breed values that would describe the risk for transmission of lens luxation (LL). This ocular disorder typical in terriers had
in this breed a frequency of approximately 2%. Simultaneously there was offered
to the breeders the ZW for size inheritance and for four hunting features:
“nose”, bay (tracking sound), working body construction, and enjoyment of
water. The number of breeds in which the Zuchtwert
evaluation is routinely used rose constantly after that. The Cynology (canine science) computer center
of the TG publishing house in Gießen, serving the
enterprises for breeding animals and stud book management, has already made it
possible to have taken care of over 60 breeds with this ZW option. With the
availability of the breed value assessment, uncertainty quickly arose over the
application and conversion of the knowledge. Since Zuchtwert
numbers are only an “estimate” and thus greatly depend on the current standard
of knowledge, selection by means of general breed warnings or prohibition for
animals with an inherited predisposition is not meaningful. It would not be
good that a bitch blocked today, then readmitted, would again be blocked with
the next evaluation. The relation therefore had to become more flexible. The
thought of not hindering breeding animals (parents) by requirements on their
individual admission or traits, but on the admissibility of a pairing, was absolutely new in the
breeding of animals. The principle of “strategic pairing” was born. Each good
animal is suitable for breeding, if it with a suitable breeding partner
produces puppies with below-average Zuchtwert
numbers.
The principle of this breed
planning was agreed upon for Golden Retrievers by the German Retriever Club
(DRC), and adopted at once by the specialty breed club for the Hovawart (RZV) as a breed strategy. While the Retriever
breeders, after the first successful breeding years, changed it from being
obligatory to a “recommendation for mature breeders” (in order to sell dogs),
the Hovawart breeders have continued to utilize this
breeding program until the present day. The attractive principle fell on
fertile soil in the RZV, for although only “HD-free” dogs were still being
bred, the by-then positive trend was again diminishing after 1984… things were
actually getting worse with the number of HD-free animals steadily declining.
With introduction of the Zuchtwert Evaluation in
1989, and with attention to the HD status of all relatives, it was now possible
to distinguish the better-producing, HD-free dogs from those more tainted by this
hereditary disease. The flexible breeding program, with its principle of
leaving untouched all bitches in the breed so that the breed's potential and
the breed continuity is protected in the kennels, turned back immediately the
trend. Today, thanks to this daring step, the 90% mark is surpassed for HD-free
animals, with a radiograph quota (percent of animals X-rayed) around 70%. [The Hovawart is a large
“yard-guard” breed with an uncanny resemblance to the Golden Retriever but
perhaps more closely related to the GSD’s ancestors.]
The Jagdterrier
breeders on the other hand had it difficult. Lens luxation
appears between the 3rd and 5th year of life on, and had often been concealed.
The honest people felt cheated and the diagnoses had not always been made by
competent ophthalmologists. So it came about that a breeding program had to be
formulated that contained, beside the Zuchtwert
assessment, also the basic conditions in reference to data gathering and
reliability: a veterinary consulting board was set up, to offer those
particular owners competent advice and help. A fund jointly held was arranged
in which each breeder would pay 10 DM per puppy. From this treasury could come
an assistance of up to 500 DM paid to soothe the buyers, around the costs one perhaps
might pay for necessary eye surgery. DNA
investigations were imposed for proof, so that the wrong parents are not
charged with the defective descendant. Altogether a campaign of instruction
with magazine articles and breeder seminars has led to the fact that now, any association with hereditary disease is taken more
responsibly and less emotionally. The breeders now feel greatly obligated
toward the breed goal. As the breed values would be published, and the
principle of strategic pairing began to be grasped (limit for pairings being no
higher than 105 average), the year's averages sank for
the lens luxation risk from year to year. The breed
average, which at the beginning had a high level of approximately 112, sank
until today it stands at 95. The frequency of the affected animals
lies in the less-than-1% range, although the reporting of it has climbed,
obviously because of the guarantee certificate that accompanies each pedigree.
One now has, through the Breed
Values, a tangible criterion of quality and can document thereby the efforts in
a breed scheme in reference to health. Successful breeding in reference to form
and performance were honored up to now with Sieger titles, championships and sports-dog awards. Surely,
it now also becomes attractive to reward the genetically healthy dog. How
important is a breeding program like that of the SV, and how important also
should be the transformation, are demonstrated by the Club for the
Additional breeds will be named,
their successful breed work supported through breed value numbers. The SV will
take stock of its own success as the radiographs and statistics for the years
1999, 2000, and later are developed. Until then, the breeders must trust the
experiences of other clubs and to observe how the breeders receive the offer
and use it. The public respect for the club will profit from the fact that
show-dog and working-dog breeding will be practiced not at the expense of, but
in harmony with, health.
Additional Comments by
Fred and Others
In January of 1999, Bill Miller
noted that while the SV had begun the “Breed Value Assessment”,
Also about a year ago, another
fancier had just completed a study of the HD-ZW ratings on the 10 VA dogs from
the 1997 German Sieger Show and the Top ten dogs from
the Bundessiegerprüfung, which should be of interest
even to the Working-only readership of this magazine. Very interesting results,
indeed:
Average for 10 VAs = 89.8 (High 118, Low
69); Average for Top 10 Trial dogs: 86.3 (High 112, Low 74).
Taking Rikkor out of the equation, the average
for VA “showdogs” would have been 86.7.
|
Specifics for Show Dogs (Bundessiegerhauptzuchtschau): |
Specifics for Working Dogs |
||||||
|
. |
Table © M.Wahl |
||||||
|
Sieger |
VA-1 |
Rikkor |
118 |
Sieger |
Place 1 |
Asko |
75 |
|
|
VA-2 |
Karly |
92 |
|
Place 2 |
Quasy |
85 |
|
|
VA-3 |
Leif |
85 |
|
Place 3 |
Nastor |
112 |
|
|
VA-4 |
Odin |
95 |
|
Place 4 |
Iriac |
74 |
|
|
VA-5 |
Jango |
86 |
|
Place 5 |
Laska |
103 |
|
|
VA-6 |
Timo |
82 |
|
Place 6 |
Feivel |
80 |
|
|
VA-7 |
Jello M. |
69 |
|
Place 7 |
Chawun |
74 |
|
|
VA-8 |
Fello |
95 |
|
Place 8 |
Dasty |
85 |
|
|
VA-9 |
Enzo |
84 |
|
Place 9 |
Oldo |
87 |
|
|
VA-10 |
Ursus |
92 |
|
Place 10 |
|
88 |
Not a significant difference in the two columns or averages; I find
many low scores in the monthly listings with “working” kennel names, but I also
find some horribly high ZWs as well. Bobbie Impellizzeri, noting that the SV allows “slightly dysplastic” dogs to be bred, took that opportunity to urge
continued reliance on OFA evaluation of hips and elbows at 2 years. As you all
know, I agree with that, but recommend adding PennHIP
info, especially at younger ages, for the ultimate in diagnostic accuracy; I
also laud the preferential use of dogs with low ZW numbers whenever possible. FL
Veterinarian Requirements and Preliminary Check List for the HD
Procedure [in Germany
Decisively involved with the
success of the battle are the SV-certified HD radiologists and HD
veterinarians. Nearly 3,000 veterinarians have become authorized by the SV as
acknowledged HD veterinarians.
Not every owner of
a German Shepherd Dog is allowed to participate in the
SV's HD program. To be able to quickly ascertain
whether the admission requirements are fulfilled, we have developed the
following checklist for you:
Ø
Minimum age: 12 months. Verify
the whelping date on the Ahnentafel
[pedigree/registration certificate].
Ø
Is the document an SV Ahnentafel? For foreign
dogs, the exhibitor must be a member of an FCI club.
Ø
Is the tattoo number correct?
Tattoo number is in the right ear - compare it with the number in the Ahnentafel.
Ø
Is it a second (repeat)
radiograph? The Ahnentafel must already carry the
stamp of a HD radiology specialist or an SV-authorized HD veterinarian, the
stamp having been recorded in the SV Headquarters.
In the case of any question about a "medium HD"
entry, only the central HD office in
HD Diagnostic Report:
Instructions for Administration
Over l5,000
HD findings are processed annually in the SV's HD
office at headquarters. For the most efficient and quickest possible
processing, the HD report was developed by the SV. Only certified "HD
veterinarians" can supply the diagnosis to the SV headquarters. Other
diagnostic reports are not acknowledged!
Please note the following instructions when filling out:
Ø
Fill out the diagnosis form
clearly and legibly (done best with typewriter).
Ø
Pressure should be strong enough
so that the 5th carbon copy will be still readable.
Ø
Please identify in the heading,
the complete name of the dog (example: Visum vom Arminius).
Ø
Always indicate the actual
owner's full name and address.
Ø
The owner must also sign the
diagnostic form. It must agree with the information on the x-ray film regarding
ownership as acknowledged by the SV.
Ø
Your stamp should be
individually on each of the carbon copies.
Ø
The date of the radiograph is
essential.
Ø
The last page of the report is
kept for your records - please send all other copies along with the film to the
SV.
One more point for your own
interest: You are not obligated to give the owner any diagnosis or judgment.
Only the finding of the central HD office in
The HD Radiograph: What
Is To Be Considered?
1. Following statements
must be on the film at time of exposure:
Ø
Tattoo number (2 letters/4
numerals)
Ø
Complete name (example: Visum vom Arminius).
Labeling with stickers or markings after developing
the film is not accepted as proof of identification. Any received without
proper identification are returned.
2. Asymmetrical pictures (poor positioning) are unfortunately a
frequent quality problem. Avoid sending such films if possible. You will
quickly be told to re-supply the specified information.
After the Radiograph
If the film is prepared
properly:
Ø
please check whether the HD -
exam stamps with the necessary information from the Ahnentafel
was placed on the film, and
Ø
immediately send the radiograph along with the report to the SV headquarters.
Early X-ray
We do not want to forbid for any
conceivable reason the early radiography of a German Shepherd Dog under 12 months age; however, the identity of
the dog must also be ensured via use of the Ahnentafel
in such cases. Therefore, a GSD should not be admitted to the early [“preliminary”] X-ray, without the tattoo number
in the ear of the dog having been conscientiously examined and compared with
the registered number in the Ahnentafel. Preliminary
readings are not of interest to the SV, however; therefore no such preliminary
HD-exam stamp will be placed on the pedigree. Also no SV diagnostic report may
be used. Such x-rays are not received or accepted by the SV.
Re-doing Tattoos [how it is done in Germany
If the dog can not be
identified: Sometimes it occurs, that a dog can not absolutely be identified
using the tattoo number in the right ear. It only remains then for the
re-tattoo by the veterinarian. Our checklist:
Ø
The pedigree must exist
naturally (not marked over an old one).
Ø
The responsible breed warden or tattooer must be at the re-tattoo. He must confirm the
identity of the dog.
Ø
Re-tattoos with the tattoo
instrument of the tattooers utilize the same tattoo
designation ("number") used at the first tattooing [or]: with your tattoo clamps and
the tattoo mark, in which the current number must be inserted beside the design
(mark) assigned to you.
Ø
Re-tattoos only in the left ear.
Ø
Local anesthesia
or tranquilizer (short-action) for dogs that are older
than 12 weeks.
[While the above is of academic interest to those who just want to know
how the SV handles it with veterinarians, or want to consider a similar program
here, the following is more for the dog owner.
********************************************************
Real GSD’s Editor’s
note: Fred Lanting
is one of only two SV conformation judges in North & Central America, and
has judged the breed in more than a dozen countries beyond that. His most
recent international assignments have included
