Detection of recessive mutations that causes complex vertebral malformation (CVM) and bovine leukocyte adhesion defi ciency (BLAD) in Holstein cattle is especially required for bulls, which are used for artifi cial insemination (A.I.); these enable elimination of carriers from the A.I. programs and therefore prevent transmission of unwanted mutations to a large number of offspring. Some breeders are also interested in the identifi cation of carriers of recessive allele for red and white coat colour (Red factor). Here, we performed genetic tests for detection of mutations associated with CVM, BLAD and Red factor using methods previously reported or modifi ed methods. Analysis of Holstein bulls, which were recommended for A.I in Slovenia in the years 2007 and 2008, revealed four (10 %) carriers of CVM, and two (5.4 %) carriers of red gene, while all bulls were non-carriers of BLAD.