Cattle are arguably the most important livestock species. Since the beginning of this century, the loss of genetic diversity within this species has been a major concern as this could have serious consequences on the ability of this species to respond to future production constraints. Genetic diversity has traditionally been accessed from pedigree, however, with the advances in molecular genetics new opportunities have emerged. We examined different methods for accessing genetic diversity and estimating genetic diversity parameters at the genomic level. We also examined criteria and strategies for the conservation of animal genetic resources. Finally, we examined genomic studies on some endangered cattle breeds.