A Breeding
policy for Minority Breeds
by G. L. H. Alderson
This article
was first presented as a paper at the annual general meeting of the British
Caspian Society in November 1979. The examples quoted in the paper relate
to Caspian Miniature Horses, but the principles of animal breeding which
they illustrate apply with equal relevance to any minority breed.
One of the most
contentious subjects in animal breeding is that of inbreeding. Some regard
it as a dangerous practice to be avoided at all costs, while others employ
a type of inbreeding (linebreeding) as a valuable aid in their breeding
programmes. Linebreeding can concentrate the qualities of an outstanding
animal in its progeny, but unplanned line breeding can reduce standards
of performance and fertility and in some cases will expose genetic defects.
Whatever its role as a factor for 'improvement', one thing is certain,
namely that inbreeding will lead to a narrowing of the genetic base of
a breed, and will and will reduce its flexibility and ability to adapt
to changing circumstances in the future. These dangers have been recognized
even by those who control the fortunes of the most popular breeds, and
they pose an appreciably greater threat to minority and rare breeds.
In every breed
there are fashionable sirs and unfashionable sires. The former are oversubscribed
and the latter are neglected, and this concentration of attention on a
relatively small proportion of elite animals can lead to a loss of bloodlines
and associated genetic material. This in turn can result in a rapidly
escalating problem when breeders search desperately for unrelated stallions
to mate to their mares. Thus in a numerically small breed there is a need
for breeders to sacrifice some of the independence of action and participate
in a broader breeding policy designed to safeguard the future interests
of the breed as a whole. Although it is not easy to persuade pedigree
breeders to accept the disciplines inherent in such a policy, from past
experience it seems it can be launched initially on a voluntary basis
and it is usually accepted without the necessity for any imposition provided
the objectives and reasons are explained sensibly.
Two Basic
Principles
The two basic principles of a group breeding policy are the maintenance
of distinct bloodlines, and the use of cyclic crossing between these bloodlines
to minimise the increase level of inbreeding. If those remnants of the
Caspian breed, which may or may not remain in Iran, are ignored there
are six extant sire lines in the breed on which to a base breeding programme.
All the stallions and mares are allocated to one of these lines according
to their type and the main influence in their pedigree. The best mares
in each line are mated to stallions in the same line (linebreeding) in
order to maintain each line as a distinct entity. The other mares are
mated to stallions in the next line in the cycle. Figure 1 (not reproduced)
shows a typical pedigree of an animal bred in this way, and its coefficient
of inbreeding is less than 1% in the first four generations.
Compensatory
Mating
The sequence of lines within the breed must be planned so that the
weaknesses of a particular line are corrected by the strengths of the
next line. This is known as compensatory mating and should be an integral
part of any breeding programme. Thus among Caspians the line based on
Daria Nour is noted for jumping ability, small size, good head and forequarters,
but is suspect on hocks and feet. In contrast the Palang line is very
good for confirmation, especially the hocks, but has a less refined head
and is taller than average. The Ruda line is of good type with a quality
head. Thus in a system of cyclic crossing the best sequence for these
three lines is Daria Nour, Palang, Ruba.
Sire Lines
and Female Families
The stallions each line are detailed in Table 1. The Ruba line is
very dominant within the breed while both the Ostad and Zeeland lines
are very vulnerable. With a group breeding programme these latter lines
must be encouraged and expanded. Strictly the Ostad line does not exist
in Great Britain in direct tail male and must be reconstructed from animals
with a high concentration of Ostad in their pedigree. The future of the
Zeeland line depends on a single stallion.
In discussions on breeding programmes undue emphasis tends to be placed
on the males, but in practice, especially in numerically small breeds,
some females emerge as powerful influences. Among Caspian mares, Taliyeh
consistently breeds good foals and is the dam of five stallions. Thus
she is contributing significantly to the danger of inbreeding. The limited
number of female families in the breed accentuates this danger and should
be counteracted by the deliberate use of as many foundation mares as possible
to breed stallions.
Incrossing
One of the problems of inbreeding is that it may lead to decreased vigour,
reduced performance and the emergence of hidden defects. Conversely the
mating of distantly related animals may produce foals of increased vigour.
While the mating of two inbred animals from different lines can lead to
a high degree of hybrid vigour. This latter technique, known as incrossing,
is used widely in plant breeding and was applied either by accident or
design in the breeding of the great Thoroughbreds of the postwar period.
Sea Bird II who won both the Derby and the Prix de l'Arc de Triumphe.
Sea Bird II was produced by mating an inbred mare from a French staying
line to an inbred stallion from an American sprinting line. The combination
of linebreeding and cyclic crossing which is recommended here, produces
incrossing.
Animals which are the product of incrossing are likely to be above average
performers, but their reputation as stallions is unlikely to match their
success on the race track. Thus there is a continuing need to use linebred
animals in the breeding programme although their own performance may not
be so outstanding.
Selection
and Culling
Traditional breeding programmes have been built around outstanding
animals such as Taliyeh. In some cases these animals are identified by
the 'eye' and skill of a breeder. In some cases the art of breeding has
been complemented by the science of genetics and the progeny test is used
more widely as a measure of excellence. But in both cases the result is
the same, namely the concentration of the breed on fewer and fewer bloodlines.
The most severe reduction in genetic material in a breed occurs when there
is extreme selection for the production of outstanding individuals, such
as Derby winners, rather than for the average quality of the breed. However
it is interesting to note that the current record for the Derby has stood
since 1935 and that for the Oaks since 1927. Despite the better tracks
improved riding and training techniques, and better nutrition, the speed
of the Thoroughbred is not increasing. It may be that a performance peak
has been reached or it maybe that inbreeding is canceling out the effects
of selection for improvement. Examples can be drawn from the inbreeding
of other species, especially pigs, to show how intensive selection has
led into a genetic cul-de-sac.
The lesson for rare breeds such as the Caspian is that attention must
not be focused on a few fashionable animals. Rather a broadly based breeding
programme must be followed with the emphasis placed on the culling of
below standard animals to raise the average quality of the breed. The
severity of the culling must be governed by population size, when a breed
is low in numbers only defective or markedly untypical females should
be culled, and relatively high proportion of stallions should be retained.
It must be a basic rule that no sire line or female family should be allowed
to die out.
Function Efficiency
As a minority breed increases in numbers the severity of culling may
be intensified to a limited degree, but still with the proviso that each
line and family is maintained. Furthermore the culling and selection should
not be unduly influenced by the vagaries of the showring fashion, but
rather by the characteristics of functional efficiency. These characteristics
include not only tooth and jaw structure, action, tail setting, etc.,
but also the ability in jumping, eventing and driving competitions, for
it is the success and publicity achieved by the Caspian in these activities
that will serve to recommend it to the wider public. The process of establishing
a breed follows four phases. First its distinctive qualities must be identified
(e.g.. jumping ability, speed temperament). Second a function must be
identified (e.g. riding pony, racing pony, eventing). Third its qualities
and performance must be documented. Fourth its value must be publicised.
Special Characteristic
The success of the whole breeding programme rests on the initial assumption
that the improvement of the distinctive characteristics is the common
aim of all the breeders. In the absence of this objective the justification
to conserve the breed is invalid. It is pointless to use the breeding
techniques described here to turn the Caspian into yet another pony of
the native British type. It is a miniature, and during its evolution in
the stony mountainous area of northern Iran, it has developed those special
qualities which are now of great value and by which it is identified.
The Caspian stands 10-12 hands high but with the graceful conformation
of a Thoroughbred or an Arab, which makes it so suitable as a riding pony.
This use, and its performance in driving trials, is further enhanced by
its kind and tractable temperament. Its hooves are tough and hard, with
a small frog, and never need showing. Its hind quarters on occasion attract
criticism from the showring devotees, but it may be that the remarkable
jumping ability of the Caspian and its powers of acceleration stem from
this aspect of its confirmation, and emphasise the need to evaluate each
animal more in the rigours of strenuous competition rather than the showring.
In this way the Caspian can hope to retain its true and distinctive identity.
Copyright Lawrence
Alderson
Lawrence Alderson
was involved with the Caspians at the beginning of their history in the
UK. He is now a trustee of Rare Breeds International, a registered charity
with aim of preventing the loss of diversity in global farm animals. To
find out more about RBI visit their website.
This article is reproduced with Lawrence's permission.
Editors note;
This paper was first presented in 1979, and yet linebreeding is as, or
even more relevant now than it was then. With each successive generation
the genes of Foundation stock become more dilute. Brian Wood the society
blood lines advisor reported that analysis of bloodlines carried by Caspians
registered in 1999 and 2000 showed that there were 11 bloodlines of 4%
or less.
Brian Wood writes in 'The Caspian' magazine
on Caspian bloodlines and can advises council on this subject.
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