Furthermore, KCNIP4, CCSER1, DPP6, MAP3K5 and GHR genes loci were identified as top 5 potential CGs with highest SNPs hit loci in all three breeds and developmental ages, while CAST gene locus was identified as potential CGs expressed with more than 100 SNPs hit in Polish HF and Hereford breeds (S30–S35 Tables). The gene discussed is CCSER1; the disease is hydrops fetalis.