The project aims are to use the information about cow's DNA profile to estimate the severity of fertility problems caused by specific genetic defects in the Swedish Red (SRB) and Holstein dairy breeds, and to estimate the economic impact of pregnancy losses caused by these genetic defects. Our goal is that the increased knowledge of known genetic defects will provide a more reliable basis for avoiding matings between carriers of specific defects, as well as to enable a selection against the causative haplotypes in practical cattle breeding and thus strengthen the dairy industry's competitiveness, sustainability and public perception. The project is an in-depth study within the ongoing SLF-funded Swedish part of the Nordic fertility project. We will work with the already collected material, augmented by Växa’s cow database and genotypes. Research funding is intended to finance the last two years of a PhD for the licentiate student within the project, Patricia Ask-Gullstrand.