Genetic diversity measures of Swiss goat breeds as decision-making support for conservation policy

Abstract

Preservation of biological diversity determines not only survival, but also adaptation to changing environments, including changes in consumer preferences. During the last century, the number of goats shrank dramatically in Switzerland but remained more or less stable in the last decade. Such a great reduction may have had serious consequences for genetic variation in the goat population. Thus, it is of interest to evaluate the current diversity in 11 Swiss goat breeds, and moreover, to offer a contribution towards conservation priorities for the different breeds. Microsatellites are among the most useful markers in assessing genetic diversity of populations; 43 were included in this study. Three clustering methods were employed to divide individuals into groups. The loss of diversity when one breed is removed from the sample was estimated by two approaches. The expected heterozygosities varied from 0.54 to 0.66. The Valais Blackneck displayed a heterozygosity deficiency and the St. Gallen Booted a heterozygosity excess. Allelic richness ranged from 4.4 to 6.2. Only the Valais Blackneck revealed a possible recent bottleneck situation. Eight of the 11 breeds were clearly unified in their own cluster (Appenzell, Boer, Chamois Colored, Grisons Striped, Saanen, St. Gallen Booted, Toggenburg, Valais Blackneck). None of these breeds is critically endangered. The breeds Nera Verzasca, Peacock and Tessin Grey assembled in one cluster only. From these three breeds, which have their origin in the south of Switzerland, the Tessin Grey is endangered due to the small population size. Most of the individuals could be assigned to their breed of origin, however, large cross-breed assignments were observed. The Weitzman, and the Caballero and Toro approaches gave differing information for genetic conservation decisions, as the Weitzman method does not account for within-breed variability. Breed conservation decisions cannot be limited to genetic diversity alone but should also consider phenotypic performances and non-profit values for the society in their cultural aspects.