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I was invited by an
English Shepherd colleague to share some comments about livestock breed
conservation as affects rare breeds and maybe not
so rare breeds of dogs. This may be a useful outside-the-box
approach to canine genetics, or it may not be useful to you at all.
Obviously there are differences between livestock and the dogs who work
them, but perhaps there are more similarities than you might think.
My
experience comes from 12 years as program coordinator of the American
Livestock Breeds Conservancy (ALBC), the U.S. nonprofit organization which
protects genetic diversity in domestic animals through the conservation of
rare breeds in ten species of livestock and poultry. Following is a
short summary of three main points in A Conservation
Breeding Handbook (1995) I co-authored with Phil Sponenberg. (For
information on ALBC or on the Handbook, consult www.albc-usa.org or
call 919-542-5704 in Pittsboro, North Carolina, USA).
1. The significance of breeds: A true breed, in the genetic sense, is a significant
agricultural resource because it is predictable
genetic package for farmers and animal breeders. Stefan Adalsteinsson
refers to the breed as a genetic heritage of survival, meaning
that each breed's unique history is reflected in its genetic makeup.
When I became an ES owner and involved in the breed, I was surprised to
find that many dog geneticists were eager to throw away the breed concept,
finding it hopeless corrupt. I think this assumption results from
only looking at corrupted breeds. In fact, conservation of the
distinct, true breeds within a species is essential to the survival of
the genetic health, breadth, and utility of that species.
There are four kinds of livestock breeds in North America:
landraces, standardized breeds, industrialized strains, and feral stocks.
The first two are of relevance here. Almost every domestic animal
breed started as a landrace. The landrace is generally a local
population that is consistent enough to be called a breed but more
variable than a
standardized breed. In livestock, landraces have been shaped by
founder
effect, geographic isolation, and environmental adaptation as well as by
breeders' goals. Landraces tend to be more consistent in complex
characteristics than they are in appearance, though they are still unique
enough to be distinguished from other breeds. Landraces generally
lack the tight organizational structure that people associate
with standardized breeds.
It is very common for people unfamiliar with landraces to deny their
existence as breeds, to'improve' them through crossbreeding until they are
nearly extinct, and to even try to destroy them, such as the
U.S. government attempting to kill all of the Churro sheep owned by the
Navajo people in the 1930s and giving them improved breeds instead that
could not survive in that extreme environment.
Standardized breeds are what most people think of when they think of
breeds; in fact, standardized breeds are the only kinds of breeds that
many people recognize as breeds. Standardized breeds began as
landraces
but were developed further when a group of breeders agreed upon a standard,
or definition, and bred towards this ideal. As a result, uniformity
and predictability were increased and diversity was reduced. There
are generally written records, a registry (or more than one), and a breed
association, all of which serve to isolate the breed genetically.
The mindset in standardized breeds is that there is a single ideal to
which all breeders should direct their intentions.
Often this ideal is the founder male (ie. Justin Morgan of the Morgan
breed).
Most landrace breeds are now becoming standardized breeds. While
there is the danger of loss of diversity in the search for greater
uniformity and organization, there may also be more potential for
conservation.
What's essential is that breeders of landraces and standardized breeds
alike recognize that there is always a balanced between the pull of
uniformity and the need for diversity.
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