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breed conservation - discover D. PHILLIP SPONENBERG, DVM, PHD VIRGINIA-MARYLAND REGIONAL COLLEGE OF VETERINARY MEDICINE VIRGINIA TECH, BLACKSBURG, VA AND - THE AMERICAN LIVESTOCK BREEDS CONSERVANCY
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steps in conservation ALBC uses these steps in conservation discover (encounter and define) secure the population sustain for the long term all three steps are needed to assure success in the survival of breeds
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discover The first step is to discover these rare breeds and populations the USA has a good informal network with an interest in the conservation of these resources
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discover this network usually indicates the existence of a population that is a candidate for conservation usually this network commits “errors of inclusion” rather than “errors of exclusion” which helps to alert conservationists misses relatively few breeds from consideration
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always better to commit “errors of inclusion” because this indicates that the network is unlikely to ignore a population that truly merits conservation discover
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part of the “discover” step is defining breeds and populations define
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ALBC uses this definition of “breed” a group of animals with a phenotype that is distinct and recognizable, and that produces this type after being mated within the population this definition is based in genetics, and establishes the breeds as genetic resources implies a certain level of genetic uniformity and predictability
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this definition of breeds ignores populations with high levels of variability, even if some of these do have cultural importance goal is the conservation of genetic resources that can be predictable as they serve agriculture define
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classes of breeds local – landrace – adapted- rustic standardized industrial feral
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classes of breeds each class of breeds needs its own appropriate strategy for effective conservation
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industrial little or nothing possible for their conservation impossible to duplicate the physical and selection environment in which these animals live high risk that some will go extinct
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standardized breeds have breed associations for their breeders standardized breeds are usually well defined conservation of these is easier than the others important to maintain a high level of genetic variation standardized breed
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few are important to conserve isolated for long times with distinct foundation and physical type feral breeds
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landrace usually well adapted usually poor documentation (history, production) poor recognition as a true breed in most places
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productive potential is poorly documented ome do have high production potential and are important to conserve and develop ost are adapted and resistant landrace
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they do need to be “genetic resources” in the strict sense need a level of genetic variation that does not prevent prediction of performance
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landrace these need to be defined carefully important to decide which animals to include and which to exclude in many cases need to rescue a breed or a bloodline without losing characteristics
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landrace need to develop strategies for long term maintenance
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landrace three steps for effective conservation Discover/ encounter/ define secure sustain Final success depends on all three steps
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for landraces it is necessary to decide if the population is truly a breed in the genetic sense “breed” in this sense is a group of animals that are similar by origin and type, and that reproduce that type after mating within the group discover
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To decide if a population is a breed depends on investigations phenotype (measured or visual inspection) history genetic data (bloodtypes, DNA fingerprints) landrace
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investigation - history ideal is long term isolation from other breeds isolation comes from geography or owner practices
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history some cases will have high levels of isolation many cases will have doubtful histories, or even more than one version of history the history and the external phenotype usually agree
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investigation - phenotype in the US few people experienced in zootechnology rare to measure animals to define breeds measurements are always more accurate but are not possible in all cases feral animals, or very extensive systems, present challenges to phenotypic evaluation – especially if measurements are needed
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phenotype look at the animals and compare them to other breeds in the area, looking for evidence of crossbreeding or mixtures with other breeds this method, even though not exact, works very well in practice
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history and phenotype usually agree most populations either have the uniformity expected of a true breed, or are very variable from crossbreeding steps one and two
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traits such as color or presence/absence of horns are usually not very important landraces usually vary more in these traits than do standardized or industrial breeds this variation doesn’t prevent use of these breeds conservation should include this variability steps one and two
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step three genetic investigations are more expensive than those for history or phenotype usually genetic investigations after the other two after eliminate populations obviously crossbred include only those that are more uniform
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genetic data genetic data are usually for relative frequencies of alleles can be analyzed different ways to reveal relationships of populations
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branching tree of breed relationships points out breed groups
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this type of “tree” also reveals the relative groupings as well as the distance of each population from the others
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complicated, but indicates individual animals, and how different they are if the population is split two ways, three, four, or five reveals fundamental points of division
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genetic results provide background for deciding appropriate strategies for conservation can reveal a mixed or uniform population can indicate animals to include or exclude step three
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DNA results can indicate relationships between breeds, and which are most distinct or distant from others step three
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some individual animals are very important for genetic variation for the future of the breed step three
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Pineywoods cattle from southeast USA adapted to a humid subtropical environment iberian origin
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Pineywoods herds isolated from one another for a century one breed or many? all of the cattle are more like one another than any other breed all of the herds have low numbers. logical to include them all in a single breed to assure their effective conservation
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Pineywoods
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BOUNDS SEAL GARNER LADNER HICKMAN DIAMOND DEDEAUX CONWAY O’NEAL PALMER VICE AGRICOLA BEACH BROADUS BAYLIS CARTER CLARK BARNES ROBINSON GRIFFEN HOLT POPPLE ALBANY EZELL KNAPP bloodlines
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Pineywoods each breeder thinks his cattle the most pure of all need to replace that attitude with more inclusion
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Pineywoods philosophy that works for this breed is to include all of the typical cattle from this region under a single registry and association cattle are inspected to exclude the herds that have evidence of influence from zebu, Devon, Angus, or Hereford
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Pineywoods these cattle vary more than standardized breeds important to include this variation dwarves and polled (hornless) cattle
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Pineywoods another breed is closely related: Florida Cracker two breeds were separated due to decisions based on regionalism of the breeders DNA results indicate these two breeds have been separated for more than a century some distinctions have arisen
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Pineywoods effective to separate the two breeds to conserve
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Pineywoods in the beginning the association encountered resistance from traditional breeders would not register cattle change to free registrations worked to increase the numbers of breeders registering cattle
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Colonial Spanish Horses similar to the Pineywoods cattle breed many herds each isolated for centuries one breed or many?
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Strains of the breed
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some herds have fewer than 30 horses impossible to maintain these in isolation for the long term, without inbreeding Colonial Spanish Horses
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total population is likely under 3,000 horses
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all of these horses are very similar to one another very distinct from other horses in the USA logical to group them together for conservation Colonial Spanish Horses
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equinos c Colonial Spanish Horses Co goal is to save the various bloodlines in several herds also to blend these into a composite mixture
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