However, studies evaluating the effect of this SNP on fertility traits in dairy cows are even more recent and scarce [28-30], with only the work from Ruprechter et al. [29] reporting a significant effect of the SNP IGF-1/SnaBI on CFS interval in primiparous Holstein-Friesian (HF) cows. The gene discussed is IGF1; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.