Narrative review evaluates genetic variation assessment in livestock using demographic and genomic measures

Genetic variation within livestock populations underpins global food security, resilience, and the long-term sustainability of breeding programs. Despite its fundamental role, harmonized approaches for assessing and monitoring genetic variation across data sources remain limited. This review provides an integrated framework for assessing genetic variation in livestock using demographic, pedigree, and genomic data, developed by FAO experts and international collaborators. Demographic indicators offer essential insight into population size, sex ratio, and reproductive structure, while pedigree data allow detailed evaluation of genetic relatedness, inbreeding, and effective population size (Ne) over time. Genomic information now provides unprecedented accuracy in characterizing allelic variation, population structure with admixture, and the dynamics of inbreeding and drift. Each data source differs in availability, resolution, and interpretive limits; therefore, complementary use of demographic, pedigree, and genomic measures is recommended for effective monitoring and decision-making. This framework outlines the main properties, applications, and constraints of these approaches and provides guidance on selecting appropriate indicators for monitoring genetic variation within and among livestock populations. Its implementation supports the objectives of the Global Plan of Action for Animal Genetic Resources and the Kunming-Montreal Global Biodiversity Framework, contributing to evidence-based management of livestock diversity worldwide.