Genetic diversity of Sardinian goat population based on microsatellites

During the last century, the selection for production traits of the main livestock
species has led to a reduction in number of local populations with consequent loss of genetic variability. In
Sardinia, the genetic improvement strategy has been based on selection for the local pure breed in sheep,
whereas in the other species (cattle, swine and goat), an often unplanned crossbreeding with improved breeds
has been applied. In this context, several studies on genetic diversity of these populations have been started
with the final aim of recovering the autochthonous genetic types. The global approach involves different steps:
- characterization of the farming system and typical products; - morphological and productive evaluation of the
animals; - genetic characterization of the populations through molecular DNA analyses (microsatellites, AFLP,
mitochondrial DNA, etc.); - creation of nucleus flocks in public farms and germoplasm banks; - organization of
herd-books involving farmers interested in the safeguard of local breeds and valorisation of traditional products.
A far as the goat population is concerned, Sardinia is the Italian region with the largest goat stock,
(209.000 heads, about 23% of the total national stock). Farms are located in mountains, low hills and even
plans (Macciottaet al., 2002) resulting in a quite large variability (Brandano and Piras, 1978) in terms of feeding
and management techniques; but extensive and semi extensive systems in marginal areas prevail (Cartaet al., 2001; Usaiet al., 2004). The current population has been constituted by crossbreeding the autochthonous
animals with other improved Mediterranean breeds,mainly Maltese goat. The aim of this paper is to study the
genetic variability of this population through the analysis of 17 microsatellite markers.