Science and Art join forces to support the endangered "Skyros small-horse"
Gembloux, Belgium - 30 August 2006
Today, Elisabeth Bömcke, a graduate student from the Gembloux Agricultural University in Belgium, presented her thesis "Conservation of animal genetic resources: the case of the Skyros small-horse breed". She received from the faculty's Jury, the highest possible grade, not only because her research was perfectly performed and presented, but also because of her high conservation consciousness. It all started in May 2005 when HORSE ART was invited by the Gembloux Agricultural University to present and exhibit its unique art collection in aid of the Skyros horse. Elisabeth became so interested in the Hellenic small-horse that she decided to dedicate her thesis to this unusual and difficult subject …
Thesis summary by Elisabeth Bömcke
Student's promoter: Professor Nicolas Gengler
2006, Gembloux Agricultural University.
Conservation of animal genetic resources:
the case of the Skyros small-horse breed.
All over the world today numerous equine breeds are endangered and some are already extinct. The problem concerns both the intra-breed diversity (decline in the number of individuals) and the inter-breed diversity (decline in the number of equine breeds). The major cause of this decrease is the disappearance of their original use, work, because of the motorization of agriculture. The absence of outlets of substitution, such as leisure and hippotherapy, significantly influenced this tendency.
Three main areas of breed conservation activities 1 , can be identified:
These three areas are all important. In attempting to choose specific breeds for conservation programmes, the following seven criteria might be considered 1 :
- Promotion of the issues involved in animal genetic resources (AnGR), i.e. increasing the public awareness about AnGR by spreading information and knowledge; promoting its teaching in schools and universities and arranging courses on AnGR for people involved in agriculture and research, both nationally and internationally;
- Documentation of existing genetic resources, i.e. description of the population sizes and phenotypic characteristics of breeds; documentation of their economic performance, of any special traits they may have, of their cultural/historical importance as well as of their genetic uniqueness;
- Establishment/support of breed conservation programmes directed toward specific breeds, which could include in situ or ex situ programmes for endangered breeds; supporting farmers willing to use breeds of lower productivity in today's economic situation or supporting genetic improvement programmes and managing inbreeding for breeds not currently endangered but which may become so in the near future.
- degree of endangerment
- species of the breed
- adaptation to a specific environment
- possession of traits of current or future economic importance
- possession of unique traits that may be of a scientific interest
- cultural or historical value
- genetic uniqueness.
In the case of the Skyros small-horse breed, Cothran (1995) 2 has proven the genetic uniqueness of the breed. The endangered status of the breed can be described today as critical, as, concentrated in some herds, this small population (less than 200 individuals in the world) is not safe from demographic accidents. As the genetics principles applied on small populations suggest, we know that the genetic variability of a small population tends to decrease during generations while the need for conservation increases, since there are less individuals and thus less 'containers' for genetic variability. Considering these threats, the Skyros small-horse breed, as a cultural and especially, genetically original inheritance, should benefit from a conservation programme.
Thus, the main objective of the study of Bömcke (2006) 3 was to estimate the relationships between the individuals of the population of Skyros small-horses and hence to make proposals to the breeders for the genetic management of the Skyros small-horse breed, i.e. to maintain the genetic variability by setting up a good mating program.
For that, the first step was the study of the recorded pedigree and the estimation of genetic variability on the bases of this pedigree. The conclusion was that the genealogical information characterizes a population with a relatively high concentration of gene origin and a relatively high level of inbreeding. But these results are not very reliable as the quality of our pedigree is poor (low percentage of known ancestors and low average number of equivalent generations). The second step was the evaluation of genetic variability within the Skyros small-horse breed using 16 genetic markers. The conclusion of this study was that the breed reflects relatively high genetic variability.
The observation is that these two steps gave contradictory results. The explanation is that inbreeding affects first the part of the genome with low genetic variability. The DNA analysis shows a high level of genetic variability so we can suppose that this level was even higher before and that the inbreeding has increased only recently (when the population decreased) and that the inbreeding effects are not marked yet at the genome level. However, the situation is critical as some alleles are present only in a few individuals (1 to 5 individuals out of 75).
- Ruane J. (1999). A critical review of the studies value on genetic distance in animal genetic resources concervation. J. Anim. Breed. Genet. 116: 317-323.
- Cothran E.G. (1995). Report on the genetics of Greek horses. Unpublished personal communication.
- Bömcke E. (2005-2006). Conservation of animal genetic resources in horses: the case of the Skyros small-horses. Graduation "mémoire". Gembloux Agricultural University, Belgium. 85pp.