Analysis of genomic data is becoming increasingly common in the livestock industry and the findings have been an invaluable resource for effective management of breeding programs in small and endangered populations. In this paper, with the goal of highlighting the potential of genomic analysis for small and endangered populations, genome-wide levels of linkage disequilibrium, measured as the squared correlation coefficient of allele frequencies at a pair of loci, effective population size, runs of homozygosity (ROH) and genetic diversity parameters, were estimated in Barbaresca sheep using Illumina OvineSNP50K array data. Moreover, the breed’s genetic structure and its relationship with other breeds were investigated. Levels of pairwise linkage disequilibrium decreased with increasing distance between single nucleotide polymorphisms. An average correlation coefficient <0.25 was found for markers located up to 50 kb apart. Therefore, these results support the need to use denser single nucleotide polymorphism panels for high power association mapping and genomic selection efficiency in future breeding programs. The estimate of past effective population size ranged from 747 animals 250 generations ago to 28 animals five generations ago, whereas the contemporary effective population size was 25 animals. A total of 637 ROH were identified, most of which were short (67%) and ranged from 1 to 10 Mb. The genetic analyses revealed that the Barbaresca breed tended to display lower variability than other Sicilian breeds. Recent inbreeding was evident, according to the ROH analysis. All the investigated parameters showed a comparatively narrow genetic base and indicated an endangered status for Barbaresca. Multidimensional scaling, model-based clustering, measurement of population differentiation, neighbor networks and haplotype sharing distinguished Barbaresca from other breeds, showed a low level of admixture with the other breeds considered in this study, and indicated clear genetic differences compared with other breeds. Attention should be given to the conservation of Barbaresca due to its critical conservation status. In this context, genomic information may have a crucial role in management of small and endangered populations.

This study aims to evaluate the current situation and diversity of indigenous cattle breeds in the Kingdom of Saudi Arabia (KSA). A survey was executed in five regions of the KSA. We recorded population sizes, phenotypes and rearing conditions. Taurine Bos taurus and zebu Bos indicus populations were found. The zebu cattle include two breeds; the Hassawi and the Janobi. The Hassawi breed was found in the eastern region and it is in decreasing number. It may become extinct soon in the absence of conservation plan. Janobi remains common with thousand animals in the south-western part of the country. Only one indigenous taurine cow, showing no phenotypic evidence of zebu introgression, was found in the Central region of KSA (Najd Plateau). This cow might be the last pure indigenous Saudi Arabia taurine animal and therefore, the breed is now close to extinction. We advocate the urgency to design conservation plan for the indigenous livestock of the KSA and to complement these with phenotypic as well as genotypic information.