EN
The aim of the study was to find out whether carriers of new genetic defect Cholesterol Deficiency (CD) occur in the population of Polish Holstein-Friesian bulls. Twenty seven bulls were included in the analysis. Bulls were selected as having in the pedigree known carrier of CD (Maughlin Storm CANM000005457798). All bulls were diagnosed by the test described by Menzi et al. (2016) by using allele-specific PCR. Among 27 bulls, 9 new CD carriers were found. Our results show that causal mutation for CD is already transmitted to Polish Holstein-Friesian cattle. The results are sufficient ground to take practical action in order to avoid further spreading of mutation causing CD.