title: Genome wide scan for somatic cell counts in holstein bulls.
abstract: BACKGROUND
  Mastitis is the most costly disease for dairy production, and control of the disease is often difficult, due to its multi-factorial nature. Susceptibility to mastitis is under partial genetic control and the industry uses indirect selection for decreased concentrations of somatic cells in milk to reduce mastitis.
  
  
  METHODS
  A genome-wide scan was performed to identify genomic regions associated with deregressed estimated breeding values (EBVs) for somatic cell counts (SCC) in Holstein bulls. In total 1183 proven bulls of the Italian of Holstein population, were genotyped with the BovineSNP50 BeadChip (Illumina, San Diego, CA) and a whole genome association analysis was performed using the R package GenABEL.
  
  
  RESULTS
  Two chromosomal regions showed association with SCC, a region on chromosome 14 with high significance (P < 5x10-6) and a region on chromosome 6 with moderate significance (P < 5x10-5).
  
  
  CONCLUSIONS
  Two regions with effects on SCC have been identified with good statistical support. A further study of these candidate regions will be performed to verify the results and identify the causal mutations.
authors.affiliation: Parco Tecnologico Padano, Via Einstein, Polo Universitario, Lodi 26900, Italy. giulietta.minozzi@tecnoparco.org.
authors.forename: Giulietta
authors.initials: G
authors.lastname: Minozzi
authors.forename: Ezequiel L
authors.initials: EL
authors.lastname: Nicolazzi
authors.forename: Francesco
authors.initials: F
authors.lastname: Strozzi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Stella
authors.forename: Riccardo
authors.initials: R
authors.lastname: Negrini
authors.forename: Paolo
authors.initials: P
authors.lastname: Ajmone-Marsan
authors.forename: John L
authors.initials: JL
authors.lastname: Williams