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This Article Full Text Full Text (PDF) All Versions of this Article: jas.2008-1760v1 87/11/3525    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Thirstrup, J. P. Articles by Pertoldi, C. PubMed PubMed Citation Articles by Thirstrup, J. P. Articles by Pertoldi, C.

Population viability analysis on domestic horse breeds (Equus caballus)¹

J. P. Thirstrup^*, L. A. Bach^,2, V. Loeschcke^* and C. Pertoldi^*,

^* Department of Biological Sciences, Ecology and Genetics, University of Aarhus, Bldg. 1540, DK-8000 C, Denmark; and Department of Theoretical Ecology, Ecology Building, Lund University, SE-22362 Lund, Sweden; and Mammal Research Institute, Polish Academy of Sciences, 17-230 Biaowiea, Poland

² Corresponding author: lars.bach{at}teorekol.lu.se

In this study, we performed a population viability analysis on 3 domestic horse breeds (Equus caballus) of Danish origin, namely, the Frederiksborg, the Knabstrupper, and the Jutland breeds. Because of their small population sizes, these breeds are considered endangered. The Vortex software simulation package was used for the population viability analysis. First, we investigated the future viability of these breeds based on present demographic and environmental parameters. Second, a sensitivity analysis revealed the most important variables for the viability of these breeds. Third, we examined management scenarios in which one of the studbooks was closed. According to the Vortex analysis, 2 of the breeds (Knabstrupper and Jutland) will persist for the next 200 yr, whereas the smaller breed (Frederiksborg) could become extinct within 40 yr. The sensitivity analyses indicated that the variables concerning reproduction of the mares had the greatest impact, with the number of mares actively breeding being the most influential on the population forecasts. The results suggest that closing the Knabstrupper studbooks can be done only if increasing the number of mares actively breeding counteracts the loss of genetic variation attributable to such a management strategy. It is recommended, based on these results, that the number of Frederiksborg and Knabstrupper mares actively breeding must be increased to approximately 30% in the 2 breeds that are presently using only 13%, while leaving the third (Frederiksborg ) at its present 30% level. Monitoring of the breeds in the future, however, may be exploited to adjust the breeding strategies. We suggest that the large amount of data required by Vortex makes it very useful for analyzing domestic animals because of the comprehensive data material often available. The results of this analysis accord with other studies on the Prezwalski horse, indicating robustness in the parameter sensitivity for horses.

Key Words: breeding simulation • management • population viability analysis • sensitivity analysis