Declining fertility is a major problem for the dairy industry. Recent developments of Omics-technologies facilitate a comprehensive analysis of molecular patters in gametes, embryos and tissues of the reproductive tract which may help to identify the reasons for impaired fertility. Large Omics-datasets require appropriate bioinformatics analysis in the context of rapidly expanding and evolving scientific databases. This overview summarizes the current status of ruminant genome projects, describes currently existing resources for ruminant genomics, transcriptomics and proteomics as well as databases and tools for the interpretation and exploitation of transcriptomics and proteomics datasets. Gene set enrichment analysis (GSEA) and transcription factor binding site (TFBS) analyses are strategies for the identification of regulatory genes. In general, the comprehensive analysis of molecular traits by Omics-technologies can enhance the interpretation of genome-wide association studies, providing insights into the biological pathways linking genotype and phenotype, and their modulation by endogenous and environmental factors.